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Biology Final

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Musculoskeletal System
Our muscles and skeletons, the effectors that produce movement.
Skeletal muscle
Striated muscle, voluntary movements, cells are muscle fibers
Cardiac muscle
heartbeat, involuntary movements, striated, cells are smaller than skeletal muscle and only have one nucleus. Cells branch and form meshwork. Made of pacemaker and conducting cells.
Smooth muscle
involuntary movement of internal organ (stimulated by movement of food). Under control of autonomic nervous system. Cells are arranged in sheets and connected through gap junctions. Can be stimulated by hormones and does not involve troponin.
Muscle fibers
Multinucleate cells of the skeletal muscle, formed from fusion of embryonic muscle cells (myoblasts). One muscle consists of many muscle fibers bundled together by connective tissue.
Myofibrils
Each muscle fiber has multiple bundles of myofibrils where the contractile proteins are found. Consist of sarcomeres.
Contractile proteins
Actin and myosin. The interaction of the filaments allows for muscle contraction.
Actin
Thin filament contractile proteins. Repeating units of actin monomers. Have myosin binding sites.
Myosin
Thick filament contractile protein. Tons of myosin molecules.
Sarcomeres
The units of contraction. Made up of overlapping filaments of actin and myosin. Distinct banding pattern within. Win they contract the z lines come towards each other.
Titin
Protein that holds myosin filaments in place. It is down the length of the myofibril.
z line
The boundary of a sarcomere, it is where the actin filaments attach
h zone
The region with no actin filaments.
A band
The entire length of the myosin filaments
Sliding filament theory
When a sarcomere shortens the actin and myosin slide along each other. The z lines move closer and the h zone becomes smaller. When the sarcomeres shorten muscle fibers shorten.
Myosin binding sites
The myosin filaments can interact with the actin filaments. In a relaxed muscle the sites are blocked.
Myosin molecule
Two long polypeptide chains twisted together with a globular head on one end.
Myosin head
They bind to specific sites on the actin molecules. The myosin changes shape and causes the actin filament to slide 5-10 nm, and this continues until the muscle is contracted.
Muscles contract
Action potentials from motor neurons initiate muscle contraction.
Motor unit
All of the muscle fibers activated by a single motor neuron. All the muscle fibers contract at the same time. The more motor units that are activated the stronger the muscle contraction will be.
Muscle cells
Can generate action potentials. They are initiated by motor neurons. Action potential is conducted to all points on the surface of the muscle fiber.
T tubules
System of tubules in the sarcoplasm of the muscle fiber.
Sarcoplasmic reticulum
Closed compartment that surounds every myofibril. Stores calcium until the muscle cell is stimulated.
Troponin
Part of an actin filament. 3 subunits. One binds with actin one binds with tropomyosin and one binds with calcium
Tropomyosin
blocks myosin binding sites on actin in resting fiber
T Tubules in action
As a result of firing an action potential they contract. An action potential arrives at the axon terminal and Acetylcholine is released. As the action potential spreads down the T tubules it opens up calcium channels and calcium is released into the sarcoplasm and in amongst the myofibrils. Released calcium stimulates muscle contraction.
part 2
Calcium is released from the sarcoplasmic reticulum and it binds to Troponin. Troponin changes shape and exposes myosin binding sites on actin. Myosin heads are attached to an ADP and a phosphate and the heads bind to actin as soon as the sites are exposed. The phosphate is released. Myosin changes shape and pulls actin filament over top of the myosin filament. The molecule of ADP gets replaced with ATP ATP breaks the bond between myosin and actin. The myosin head goes back to normal.
Intercalated disks
mechanical adhesions between adjacent cells
Gap junction
form cytoplasmic connections between cells
pacemaker and conducting cells
do not contract initiate and coordinate rhythmic contractions of the heart. P(creates signal to beat) C(carry information from the pacemaker to the ventricles.
Myogenic
Generated by the muscle itself. Pacemaker can maintain the heartbeat without info from the CNS. Based on the cns' info of blood levels it can increase or decrease the heart rate.
Gap junctions of smooth muscle
Electrical connection, action potential in one cell in a sheet can spread to all other cells.
Plasma membranes in smooth muscle
They are sensitive to stretch. Stretched cells depolarize and fire action potentials.
Smooth muscle contraction
Calcium influx to sarcoplasm is stimulated by stretching action potentials or hormones. Calcium binds with calmodulin. It activates myosin kinase which phosphorolates myosin heads. Myosin can bind and release actin.
Twitch
Minimum unit of contraction. Generated by single action potential. Force generated depends on how many muscle fibers are in the motor unit. Tension generated depends on motor units available and the frequency at which they are firing.
Tetanus
Action potentials are so frequent that calcium never cleared from the sarcoplasm. So there is a continuous contraction. Depends on a supply of ATP. ATP is needed to break the actin myosin bond and "re-cock" the myosin head. To maintain contraction the cycle has to continue.
Muscle tone
Many muscles of the body maintain a low level of tension when the body is at rest. Activity of a small but changing number of motor units.
Slow-twitch fibers
have more mitochondria. Oxidative or red muscle. Contains myoglobin. Maximum tension is low and develops. Highly resistant to fatigue. Have good reserves of fuel so they can maintain ATP production.
Fast-twitch fibers
Glycolitic or white muscle. Very little myoglobin. Maximum tension is high and develops quickly. Fatigues rapidly. Fibers cannot replenish ATP fast enough to sustain contraction for long periods of time. Good for short term work.
Anaerobic exercise
Increases strength. The bigger the muscle the stronger the muscle. Weight lifting repeatedly contracts specific muscles under heavy loads until fatigued. Minor tissue damage. Muscle fibers get bigger
Aerobic
Increases endurance. Increases the oxidative capacity of the muscle. Increases the number of mitochondria and myoglobin.
Skeletal systems
Provide rigid supports against which muscles can pull.
Endoskeletons
An internal scaffolding to which the muscles attach. Advantage is that it grows with the animal. Humans have 206 bones.
Axial skeleton
the part of the skeleton that includes the skull and spinal column and sternum and ribs
Apendicular skeleton
Everything but the skull spinal column sternum and ribs
Cartilage
Tough rubbery mix of polysaccharides and proteins. Stiff and resilient but somewhat flexible. Joints, ear, larynx and nose.
Bone
Extracellular matrix of calcium phosphate. Made of osteoblasts and osteoclasts.
Osteoblasts
build up and lay down new bone.
Osteocytes
Osteoblasts that get trapped in the material that gets laid down
Osteoclasts
Break down the bone, they reabsorbe and erode bone, forming cavities and tunnels.
Membraneous bone
Outer bones of skull
cartilage bones
forms 1st as cartilage then slowly ossifies. limbs
Bone structure
compact or cancellous
compact bone
solid and hard
cancellous
appears spongy
Bone stops growing when...
The outer cites and the center sites fuse.
Haversian bone
Compact bone centered around haversian canals. The osteoblasts lay the bone down in rings.
Joints
Flexor and extensor. Muscles exert force in only one direction. Muscles work in agnostic pairs.
Flexor
The muscle that bends a joint
Extensor
The muscle that straightens a joint.
Ligaments
Bands of connective tissue that holds bones together at the joints.
Tendons
Connective tissue straps that attach muscles to bones.
Respiratory Gases
Oxygen, carbon dioxide, exchanged by diffusion.
Barometric pressure
Pressure exerted by the atmosphere. At sea levels its 760mm of Hg. In a vacuum the pressure is zero.
Partial pressures
concentration of different gases in a mixture. O2 makes up 20.9% of atmosphere
Amount of oxygen
20.9% of atmosphere. There is no change in the amount of oxygen in the atmosphere at any height.
Fick's law of diffusion
The variables that have an effect on the rate of diffusion of a substance. Increase surface area (A) increase diffusion rate. Increase distance (L) decrease diffusion rate.
Water vs. Air
O2 content of air is higher. It diffuses 8,000 times faster from air than in water and it takes more energy to move water over the respiratory surfaces than it does air.
Air breathing water problems
Mitochondria are bathed in water containing solutions, hard to get O2. Because we are filled with water its hard to diffuse oxygen and we have specialized respiratory systems with large surface areas to get more O2.
Ocean creatures
Flat worms have no respiratory systems but their body is so flat that the distance between their cells and body surface is so small that they can exchange gases.
High temp. problems
Most water breathers are ectothermic so they need more O2 as temperatures increase. Warm water holds less o2 than cold water.
Increase in altitude
At all altitudes O2 makes up 20.9% of atmosphere but the barometric pressure decreases. Diffusion of O2 depends on partial pressure differences.
CO2
Is lost by diffusion as O2 diffuses in. Rate of diffusion depends on the partial pressure gradient. Amount of CO2 in the atmosphere is very low. Makes up .03% of atmosphere.
Maximize gas exchange
Increase in surface area, maximize partial pressure gradients, minimize diffusion differences.
Circulatory system
Some animals do not have circulatory systems. Open and closed.
Open circulatory system
No distinction between blood and tissue fluids. Arthropods. They do have heart that pumps blood through the vessels but it eventually mixes with the fluid.
Closed circulatory system
Blood and tissue fluids are separate. Heart pumps blood through the system.
Advantages of closed circulatory system.
Blood moves more rapidly. Blood can be directed to specific tissues. Diverting blood flow to things that are working. Large molecules remain inside vessels, don't loose important proteins or RBC in tissues. Supports higher levels of activity.
Vertebrate Circulatory systems
Closed Circulatory systems and hearts with 2+ chambers. Increased separation of oxygenated and deoxygenated blood. Two different circuits, pulmonary and systemic.
Oxygenated blood
Blood thats going to tissues, filled with O2
Deoxygenated blood
blood thats returning from tissues, O2 is mostly gone.
Pulmonary
having to do with the lungs
Systemic
relating to the whole body rather than only a part
Arteries
blood vessels that carry blood away from the heart
Arterioles
small vessels that receive blood from the arteries
Veins
blood vessels that carry blood back to the heart
Capillaries
tiny, thin-walled blood vessels that allow the exchange of gases and nutrients between the blood and the cells of the body
Venules
small vessels that gather blood from the capillaries into the veins
Blood flow
Arteries > arterioles > capillaries > venules > veins
Fish Circulation
2-chambered heart, single atrium and ventricle, very little separation of oxygenated and deoxygenated blood. Low pressure in capillaries which is a disadvantage.
Lungfish circulation
3 chambered heart, still mixing of oxygenated and deoxygenated blood but they are separated in the heart. Have the ability to bypass the gills and have the blood go through the lungs.
Amphibian Circulation
3 chambered heart, 2 atria and a ventricle. Still mixing of the blood but there is a separation of pulmonary and systemic circuit. Maintains the two under different pressures. They can also absorb oxygen across their body surface.
Crocodilian Circulation
4 chambered heart. Complete separation of blood and systemic and pulmonary. They can control when they breathe, they can bypass circulation in their lungs by increasing pressure so it goes through to the systemic.
Birds and Mammals
4 chambered heart, Complete separation.
Advantages of separate circuit
No mixing of oxygenated and deoxygenated blood. Maximal respiratory gas exchange. The two circuits can operate at different pressures.
Human Heart
Right side - deoxygenated. Left side - oxygenated. Valves.
Atrioventricular Valve
A valve in the heart between each atrium and ventricle that prevents a backflow of blood when the ventricles contract.
Pulmonary Valve
prevents blood from flowing back into the right ventricle after it has entered the pulmonary artery
Aortic Valve
prevents blood from flowing back into the left ventricle after it has entered the aorta
Pulmonary Vein
carries oxygenated blood from the lungs to the heart
Optimizing partial pressure gradients
Minimize the diffusion path length. Ventilation and perfusion.
Ventilation
Exposes the gas exchange surfaces regularly to a fresh respiratory medium. PO2 high and PCO2 low.
Perfusion
Circulating blood over the internal side of the exchange surfaces. PO2 low and PCO2 high.
Gas exchange system
A gas exchange system consists of the organisms gas exchange surfaces plus the ventilation and perfusion systems
Insects
System of air tubes that provide all cells of the body with an ample supply of oxygen. Tracheae branch into tracheoles and these branch into air capillaries. This allows insects to remain small. O2 is brought into the insect by spiracles.
Fish Gas Exchange.
The fish gills provide a very large surface for gas exchange between the water and the internal environment of the fish. There is a unidirectional flow of water over the gills. The gills are protected by opercular flaps.
Gills
Each gill consists of hundreds of gill filaments, each gill filament has rows of folds called lamellae that serve as gas exchange surfaces.
Countercurrent flow
Blood flows in the opposite direction of water. This is more efficient and the blood will eventually reach a point of almost 100% saturation. The water is always more saturated than the blood so there is a gradient of oxygen.
Bird lungs
Birds maintain high levels of activity. They have smaller lungs than mammals and they have a unidirectional flow of air through the lungs. Their lungs expand during exhalation and contract during inhalation. Fresh air never mixes with stale air. A
Air flow in Birds
During inhalation the air is taken not directly into the lungs but first into the posterior air sacs. During exhalation the air sacs contrat and push the air into the lungs. During the next inhalation the air flows into the anterior air sacs. In the next exhalation the air is expelled.
Tidal Volume
The amount of air that moves in and out per breath.
Inspiratory reserve volume
The amount of air you can take in thats above and beyond the normal tidal volume.
Expiratory reserve volume
The amount of air you can breathe out above and beyond the normal tidal volume.
Residual Volume
Volume of air that is always present in the lungs. It is the air that makes up the difference of vital and total lung capacity.
Alveoli
The sights of gas exchange in the human lungs there are 300 million alveoli in the human lungs and the combined surface area of all of them is about 70 m^2. They are surrounded by networks of capillaries that also have very thin walls.
Bronchioles
the smallest tubes of the bronchus. Coming from the bronchi that contain clusters of alveoli at each end.
Mucus
Collects dirt and microorganisms that are inhaled. Mucus elevator.
Mucus elevator
interior surfaces of the airways down to the respiratory bronchioles are lined with ciliated epithelial cells. Mucus coating traps particles in the air. Beating of the cilia push particles up to the pharynx where they are swallowed.
Surfactant
Reduces the surface tension of alveoli walls. Premature babies do not have this.
Transporting O2 and CO2
Transported by the blood (perfusion). The blood plasma only holds small amounts of O2. Hemoglobin binds to 4 molecules of O2.
Hemoglobin
iron-containing protein in red blood cells that transports oxygen from the lungs to the tissues of the body. The ability of hemoglobin to bind to or release O2 depends on the partial pressure of O2 in the environment.
Hemoglobin composition
alpha, beta or gamma chains. 2 alpha and 2 beta in adults, 2 alpha and 2 gamma in fetal humans.
Affinity of Hemoglobin
Changes in environment have an affect. When the pH is more acidic the hemoglobin releases more O2 into the tissues. When there is BPG in the blood it binds with hemoglobin and lowers the affinity for O2 so more oxygen goes to the tissues and not lungs.
Myoglobin
O2 binding molecule found in muscle cells. Higher affinity for O2 than hemoglobin. Provides muscle cells with a reserve supply of O2. Diving mammals have high concentrations so that their muscles do not get starved of oxygen when they go underwater.
Transporting CO2
CO2 can decrease pH of blood stream. CO2 is diffused from cells into the plasma. Some CO2 remains carried in the plasma some binds to hemoglobin but the majority is converted to bicarbonate ions. CO2+H20 > H2CO3 > HCO3- +H+. In the lungs these processes are reversed. CO2 goes out of the bloodstream into the lungs and it is exhaled.
Buffer CO2
It maintains ph in the solution. Can either bind to excess H+ or increase H+ as needed.
Breathing regulation
Controlled in brain stem. Pons regulates normal breathing. When the brain chord is severed above the medula the person breathes irregularly. The pons can change breathing in respons to increasing levels of CO2.
Asexual reproduction
Does not require mating
Little genetic diversity
Mostly sessile.
Takes a lot less energy than sexual reproduction. Much more efficient.
Three types of asexual reproduction are budding, regeneration, and parthenogenesis.
Budding
offspring grow as a bud off the parent as a completely new organism. And it grows until it is ready to be independent, sometimes even to the full size of the parent.
Regeneration
Usually thought of as a re-growing of a leg but some can create a whole new organism. A starfish can grow into a new organism if a leg is cut off as long as it contains part of the central disk.
Parthenogenesis
The development of offspring from unfertilized eggs.
- May determine the sex of the offspring.
--Ones that develop are usually males and then females will develop as the fertilized egg.
Females can act as males in some species
-Depends on cyclic hormonal states (estrogen and progesterone).
--Act of mating is still sometimes needed in these organisms. Initiates the production of eggs even if they do not get fertilized.
Sexual Reproduction
Two parents produce specialized cell types (gametes) that fuse (fertilization) to form a new individual.
Promotes genetic diversity
- crossing over (crossing over of their information) and independent assortment (chromosomes separate independently of one another)
3 steps: gametogenesis (production of gametes), mating (brings gametes together) and fertilization (gametes fuse together)
Gametogenesis
Specialized type of cell division called meiosis. (End up with half genetic information in daughter cell.)
Gametes have half the number of chromosomes
Gametogenesis occurs in
Testes in males; gametes are small, motile sperm.
Ovaries in females; (much larger than sperm) gametes are non-motile ova, or eggs.
Gametes are produce from germ cells. Germ cells give rise to pregametes which go through meiosis to the sperm or eggs.
Spermatogenesis
Continuous process in human adult males.
Primary spermatocytes undergo meiosis to form 4 spermatids
spermatids
Mature in testes to form sperm
Rigid between spermatids
they remain connected because the x chromosome only gets put into half the spermatids, the other half has a y chromosome. The information from the x is needed for the final maturation of the sperm.
Oogenesis
the production, growth, and maturation of an egg, or ovum. A discontinuous process in human females.
Primary oocytes are formed during fetal development.
Primary oocytes
Females are born with every oocyte they will ever have. Sit arrested in the first stage of meiosis until puberty. (can stay in that stage from weeks to years). After puberty: each month a few oocytes are triggered to continue through meiosis.
Only one completes meiosis and is released as the ovum (menstrual cycle)
Oogenesis 2
Primary oocytes undergo meiosis to form 1 ovum and 2 polar bodies
1◦ oocyte 2◦ oocyte + polar body
2◦ oocyte ovum + polar body
Ovum
very large, large amount of cytoplasm, surrounding matrix for protection
Fertilization
Union of a haploid sperm and a haploid egg. Creates a single diploid cell, called a zygote
Fertilization steps
-Sperm has to find and recognize the egg
-Sperm penetrates matrix surrounding the egg
-Plasma membranes fuse
-Egg blocks entry of additional sperm (changes it's plasma membrane)
-Egg activation (going through second meiotic division)
-Egg and sperm nuclei fuse
Acrosome reaction
Acrosome in head of sperm ejects contents. Enzymes allow penetration through protective matrix.
Sperm and Egg Interactions
Recognition occurs through receptors on the surface of sperm and egg, Acrosome reaction, Fusion of egg and sperm membranes
Sperm and Egg Recognition
Species and cell type specific. (Organisms that use external fertilization the sperm has to make sure that the egg is the same species)
Fusion of Egg and Sperm
Allows sperm nucleus to enter egg cytoplasm
Fast Block to Polyspermy
Not seen in mammals. Rapid electrical depolarization of membrane potential (bunch of sodium atoms changes the environment in the egg)
Slow block to Polyspermy
Converts vitelline envelope (zona pelucida) to a physical barrier sperm cannot penetrate. Calcium levels rise in egg cytoplasm.
Fusion of Nuclei
Forms a Zygote. Whose nucleus contains complete set of chromosomes. Half from each parent.
External Fertilization
Aquatic environments. Gametes are released into the environment (usually thousands of thousands) because not everyone will be fertilized.
Internal fertilization
Required for mating on dry land. Sperm are deposited within female reproductive tract (increases likelihood of fertilization)
Copulation
the joining of the male and female accessory organs
Primary sex organs
produce gametes and serve endocrine functions. Testes in males, ovaries in females
Accessory sex organs
All additional anatomical components of an animal's reproductive system. Penis in males, vagina in females, glands, tubules, ducts, and other structures. (Prostate gland)
After fertilization the egg is...
Laid (oviparous animals - birds, reptiles). Retained to develop internally live birth (viviparous). In mammals, it implants into the uterus. Embryo is fed via the placenta.
Sperm
Produced in the seminiferious tubules of the testes, stored in the epidydimous.
Spermatogenisis
The production of sperm. Stimulated by testosterone and follicle simulated hormones.
Leydig cells
A cell that produces testosterone and other androgens and is located between the seminiferous tubules of the testes.
Testes
Located outside the mammalian body because the optimal spermatogenesis temperature is lower than body temperature.
Sexual arousal
Spongy tissue of penis becomes filled with blood and penis becomes erect. Sperm move through vas deferense and urethra to base of penis.
Ejaculation
muscle contractions force semen out of the urethra
Eggs
Produced in the ovary and released into the oviducts. Fertilization occurs during the trip down the oviduct. Embryo implants in the endometrium of the uterus.
Ovarian Cycle
Release of eggs
Uterine cycle
Preparation of the endometrium for implantation
Menstrual Cycle
Repeats every 28 days if no implantation occurs. Controlled by estrogen, progesterone, LH, FSH. Day 1 of cycle is the endometrium sloughs off and menstruation occurs.
MC before day one
Slight rise in FSH and LH. Development of a few 1* oocytes and their surrounding cells (the follicle).
Follicle
cluster of cells surrounding a single egg in the human female reproductive system. Follicle cells secrete estrogen in response to LH/FSH
MC Day 5-12
Slow rise in estrogen levels, follicle continues to develop. Endometrium growth is stimulated. Negative feedback of LH/FSH
MC 12-14
Above a critical level of estrogen in bloodstream, LH and FSH secretion is stimulated. Spike in LH and FSH levels cause follicle to rupture and release the egg (ovulation) Follicle cells produce progesterone.
Ovulation
The process by which a mature egg is released from the ovaries into the fallopian tubes.
corpus luteum
endocrine tissue which produces hormones, estrogen, and progesterone which prepares the uterine lining for receiving an embryo
MC 14-28
Progesterone rises, estrogen falls. Stimulates development of endometrium in preparation for pregnancy. LH and FSH levels decline.
Absence of implantation
Corpus luteum degenerates. Progesterone levels drop. Endometrium sloughs off and the cycle begins again.
If fertilization occurs
Embryo implants in uterus around day 20. Stimulates embryo to produce hCG.
hCG
Human chorionic gonadotropin. Maintains corpus luteum which stimulates progesterone and estrogen production. Presence of hCG in the blood is the basis for pregnancy testing.
Labor
The onset of labor is triggered by hormonal and mechanical stimuli. Progesterone inhibits contractions. Estrogen stimulates contractions. Near the end of pregnancy the ratio shifts in favor of estrogen. Onset is marked by increase in oxytocin.
Immune System
a system that protects the body from foreign substances and pathogenic organisms by producing the immune response. Recognition, activation, effector phases.
Innate Immunity
1st line of defense. Not specific, no memory, fast acting. Found in virtually all animals and plants. Activation of defensive cells and secretion of defensive proteins.
Adaptive Immunity
Found in vertebrates. Aimed at specific pathogens. Slow to develop. Has memory. Can distinguish self from non self.
Blood Plasma
Contains ions, small molecular solutes, soluble proteins. Red and white blood cells.
Red blood cells
Erythrocytes. Majority of blood plasma.
White blood cells
Leukocytes. Can exit and cross into the lymph. Phagocytic and lymphocytes.
Phagocytic cells
Engulf invading cells and destroy. Like pac man.
Lymphocytes
B cells (produces antibodies) and T cells (regulates activities of other leukocytes
Lymph
Fluid derived from interstitial fluid. Collected in vessels that return it to the blood. Lymph nodes. Contains lymphocytes that can initiate an immune response because they constantly monitor the lymph.
Antibodies
Proteins that bind to and "tag" anything identified as non-self. Produced by B cells.
MHC
Major histocompatibility complex proteins. "Present" fragments of molecules to the immune system.
MHC I
found on the surface of most cells, identifies the cells as self
MHC II
on the surface of antigen presenting cells, identifies as not self
T-Cell receptors
Proteins on T cells that bind non-self molecules presented by MHC proteins on other cells.
Cytokines
Signaling molecules secreted by immune cells. Activate B cells, macrophages and T cells.
Epithelial cells
Form first line of defense. Physical barrier. Secrete defensins. Lysozymes. Natural flora we live with try to kill the bacteria and don't give them room to grow. (ii)
Defensins
Skin cells produce them. They are polypeptides that kill bacteria or virus(ii)
Lysozyme
secreted by some glands, attack cell walls of bacteria. (ii)
Complement proteins
Proteins that act in a cascade with each protein activating the next. Attach to a microbe, activate the inflammation response to attractive phagocytes, lyse invading cells. (ii)
Interferon proteins
Class of cytokine. Produced by infected cells. Important in defense against virus. (ii)
Phagocytes
Travel freely in the lymph and circulatory systems. Recognize pathogenic cells, viruses or fragments of these natural invaders. Antigen presenting cells. (ii)
Natural Killer cells
Detect infected cells and some tumor cells and destroy. (ii)
Inflammation
Response to injury. 1st responders are mast cells. Blood vessels become dilated and leaky. Phagocytes are attracted to the area. (ii)
Mast cells
Release chemical signals, like tumor necrosis factor, prostaglandins, and histamine.(ii)
Humoral Response
B cells that produce antibodies bind cells to a specific antigen. The B cells are activated by T helper cells. Antibodies bind to and coat the object that contains the antigen. Phagocytic cells engulf and digest the target. (ai)
Cellular Response
Cytotoxic T cells that bind to specific antigen MHC complexes that are activated. Self cells that express this foreign antigen are induces to kill themselves (apoptosis). Effective in combating intracellular pathogens.(ai)
Humoral + Cellular
Activation requires that antigens be "presented'' to the T cells. T helper cells are the connection between the two.
Antigen-Presenting cells
APC's. They expose the structure of the antigen to the T and B cells. The antigens are exposed in the context of MHC proteins on the cell surface.
Plasma cells
Develop after T helper cells bind to the same antigen. T helper cells release chemical signals. Plasma cells have increased amounts of ER and ribosomes. Produce large amounts of antibody proteins and are specific for one antigen.
Cytotoxic T cells
Find virus infected cells or mutated cells.
T helper cells
Assist both the humoral and cellular responses. Releases cytokines after binding to an AP macrophage. Proliferates creating clones.
cytokines
activate B cells and they proliferate. Stimulate B cell proliferation and plasma cell formation and produce antibodies.
Activation Phase
virus-infected or altered cell displays peptide fragments bound to MHC I. A Tc cell recognizes and binds to the complex and proliferates.
Effector phase
Tc clones recognize other infected cells, bind to them and initiate lysis. Tc cells recognize self MHC proteins complexed with foreign or altered fragments. Helps rid the body of its own infected cells.
Allergic reactions
Occur when the immune system overreacts or is hypersensitive to an antigen. Antigen may not be a danger but it produces inflammation and other symptoms. Large amounts of IgE are produced, second exposure results in histamine release.
Autoimmunity
Clones of B and T cells are produce and are directed against self antigens. Why? Failure of clone deletion. Molecular mimicry - self has antigens that resemble nonself and are recognized by T cells.
Nervous system
Networks of interacting neurons (10^11 neurons). Information is passed from one neuron to the next at synapses. A single brain neuron can receive information from 1,000 synapses at any given time.
Afferent neurons
carry information into the nervous system. This information comes from sensory neurons.
Efferent neurons
carry commands to the effectors (muscles, glands)
Interneurons
facilitate communication between sensors and effectors
Nerve net
neurons that allow the organism to interact with the environment.
Cerebral hemisphere
Complex thinking, memory, language, social interactions
Presynaptic neuron
already fired (before the synapse)
Post synaptic neuron
gets information from the presynaptic
synapse
the junction between two neurons (axon-to-dendrite) or between a neuron and a muscle
Cell body
Contains nucleus and organelles
Dendrites
Receive information
Axon
Conducts nerve impulses
Axon terminals
Synapse with a target cell
Glial cells
Support the neurons, supply nutrients, maintain the environment, consume cell debris. Insulation of neurons (allows signals to travel faster)
Schwann cells
Supporting cells of the peripheral nervous system responsible for the formation of myelin.
Oligodendrocytes
help function in brain
Astrocytes
form the blood brain barrier and prevent the neurons in the brain from toxins.
Membrane Potentials
A difference in voltage across the plasma membrane of a neuron
Resting membrane potential
The voltage difference across the membrane of a resting cell (neuron has not been stimulated)
Action potential
The most extreme change in membrane potential (nerve impulse). 1-2 milliseconds. 100m/s. Jumps from -60mv to 50mV. After this jump sodium channels are opened.
Neurons
Have a plasma membrane that is impermeable to ions. There are different concentrations of ions inside and outside the cells.
Ion pumps
Require energy. Move ions across the concentration gradient. From lower to higher concentration. Sodium-potassium pump. Pumps Na+ out and K+ in. K+ is greater inside than in the extracellular fluid.
Ion channels
Permits diffusion of ions across membrane. Is selective for specific ions and can be either in an open or closed position
Electrochemical gradient
Combination of the concentration gradient and voltage difference across the membrane
resting potential
Resting neurons contain a lot of open K+ channels. It is the potential at which net diffusion of K+ out of the cell stops. Approx. -60mV
K+ Channels
Establish the resting membrane potential, K+ diffuses down its electrochemical gradient
Voltage gated channels
Open or close in response to a change in the voltage across the plasma membrane
Chemically gated channels
Open or close depending on the presence or absence of a specific molecule that binds to the channel protein
Mechanically gated Channels
Open or close in response to mechanical force applied to the plasma receptor
Depolarized
Voltage gated Na+ channel opens
Hyperpolarized
Chemically gated K+ channel open
Action potential AoN
All or nothing. Opening of voltage-gated Na+ channels is under the control of positive feedback.
Self-regenerating
The action potential spreads by current flow to the adjacent regions of the membrane.
Myelin
Axons of nerve cells are wrapped in myelin. It electrically insulates the axon. The covering is not continuous.
Nodes of Ranvier
Areas where axon is not covered. Clusters of ion channels are at these points.
Saltatory conduction
Rapid transmission of a nerve impulse along an axon, resulting from the action potential jumping from one node of Ranvier to another, skipping the myelin-sheathed regions of membrane.
Neuromuscular Junction
Synapse between a motor neuron and a muscle cell. Neurotransmitters like acetylcholine.
Motor end plate
A modified part of the muscle cell plasma membrane. Small number of voltage-gated sodium channels.
Synaptic cleft
Space between the pre- and post- synaptic cells. ~20-40nm
Excitatory synapses
If neurotransmitter causes depolarization of the postsynaptic cell.
Inhibitory
Neurotransmitter causes hyper polarization of the post synaptic cell. Y-amino butyric acid(GABA) and glycine
Axon hillock
The decision making area of the neuron. Not myelinated. Contains many voltage-gated ion channels. If depolarized to threshold an action potential will be fired.
Turning of Neurotransmitters
Degraded by enzymes. (Acetylcholinesterase, nerve gases) Neurotransmitter diffuses away from the synaptic cleft. Taken up by adjacent cells.
Ionotropic
receptors controlling ion channels
Metabotropic
Not ion channels. Transmembrane proteins that initiate an intracellular signaling process. Linked to G proteins (located inside the cell)
Sensory Cells
Receive physical or chemical stimuli. Convert stimuli into signals that are sent to other parts of the nervous system. Alter the flow of ions across the plasma membranes.
Ionotropic sensory receptors
Directly influence the channels. Pressure sensitive, temperature sensitive, voltage gated.
Metabotropic sensory receptors
Indirectly open channels. Taste/smell/light.
Sensations
Detect different sensations. Many different receptors in a given area. Sensory cells send information to the Central nervous System. Information from different kinds of sensory cells arrive at different places in the CNS.
Phantom limb
sensations that appear to orginate in a limb that has been amputated
Stretch receptor
receptor dendrites depolarize in response to stretching of the muscle tissue
Sensory adaptation
Some sensory cells give diminishing responses to repeated stimulation. Allows animals to ignore background conditions
Chemoreceptors
Respond to specific molecules. Taste and smell. Information elicits powerful behavioral and physiological changes.
Pheromones
Chemical signals used to attract mates. EX. Silkworm moth. Pheromone: Bombykol. Receptors are on the antennae of the male. Males several km away can detect bombykol.
Vomeronasal organ
a portion of the mammalian olfactory system that is sensitive to pheromones
Olfaction
Sense of smell. Neurons embedded in epithelial cells of nasal cavity. Axons extend to the olfactory bulb of brain. Dendrites end in olfactory hairs. Epithelium is protected by a layer of mucus.
Olfactory hairs
cilia that bind to molecules called odorants.
Gustation
Sense of taste. Taste buds. Humans perceive 5 tastes. Sweet sour salty bitter umami.
Taste buds
Human tongue has around 10,000. Located on the papillae and they aren't neurons.
Umami
recently recognized and only defined as "savory", "meaty", "delicious"
Plants
Came from most likely green algae, developed from an embryo protected by parent tissues, Cellulose in cell walls, chloroplasts use chlorophyll's a&b, use starch as a major energy storage carbohydrate
Plant adaptation
appeared 400 to 500 million years ago and they needed a way to transport water to all parts of the plant, structural support and methods to disperse gametes
Waxy Cuticle
covering that slows water loss
Stomata in the leaves
Openings in stems and leaves, regulates gas exchange
Gametangia
enclose and protect gametes from drying out
Embryos
contained in a protective structure
spores
reproductive particle
pigments
provide protection against uv radiation
Mutual association with
fungus
Life Cycle
Includes a multicellular diploid and a multicellular haploid stage.
Gametes
produced by mitosis
Meiosis
produces spores that develop into haploid organisms
Sporophyte
multicellular diploid plant, produces spores in the sporangia by meiosis, spores develop into a haploid plant
Gameotophyte
multicellular haploid plant, produces gametes by mitosis, gametes fuse during fertilization to produce the diploid sporophyte embryo
Gametophyte generation
non vascular
soporophyte generation
vascular
non vascular plant
liverworts, mosses, hornworts, have a thin cuticle and grow in moist environments in dense mats, lack leaves stems and roots
Xylem
(vascular plants) Conducts water and minerals from soil up to the rest of the plant, cell walls contain lignin
Phloem
conducts products of photosynthesis throughout the plant
Tracheid
specialized cell
Branching sporophyte
not dependent on the gametophyte
heterospory
two types of spores develop into separate male and female gametophytes, all seed plants
Wood stems
proliferation of xylem, called secondary growth
Gymnosperms
pines and cycads
Angiospersms
flowering plants
Megasporangia
female gametophyte
Microsporangia
male gametophyte
Seed
may remain viable for years, germinate when conditions are favorable, seed coat prevents drying and provides protection
Naked seeded plants
Ovules and seeds are not protected by ovary or fruit tissue, conifers
Double fertilization (angiosperms)
2 male gametophytes: one combines with the egg, one combines with the other cells and will form the endosperm
Stamens
bear microsporangia, filament and anther
carpels
bear megasporangia, one or more carpels form the pistil, stigma, style and ovary
petals
corolla
sepals
calyx
Pollination
Everything in flowers are modified leafs. Pistal is where the mega gametophyte is located. Surface is called the stigma, the stalk is called the style, then the ovary and ovule. The stamen has the anther on top and that holds the pollen grains. When fertilization takes place theres a formation of a pollen tube, that the pollen grain can move down, one fertilized an egg and one fertilizes the endo spore, which provides nourishment for the seed.
Perfect flowers
have both mega and microsporangia
Imperfect flowers
either mega OR micro
monoecious
male and female flowers occur on the same plant
Dioecious
male and female have separate flowers
Inflorescence
many flowers grouped together
Fruits
ovary and seed develop
All animals are...
Multicellular, Heterotrophs, use internal digestion, some...move
Animals share a common ancestor?
Similarities include, special types of cell-cell junctions, common extra cellular matrix molecules, similarities in their Hox genes
Hox Genes
Genes that direct development, specify body pattern and axis formation
What are the closest relatives to animals?
Choanoflagellets are thought to be the most ancient and they closely resemble the feeding cells in sponges (choanocytes)
How to determine the evolutionary relationships of animals?
fossil record, patterns of embryonic development, the physiology of the organism and ribosomal RNA sequences
What separated first?
Sponges, cnidarians, ctenophores
Protostomes
The blastopore forms the mouth. Bilaterally symmetrical. Bodies have two major traits: anterior brain and ventral nervous system. Radial cleavage pattern.
Deuterostomes
The blastopore forms the anus. Bilaterally symmetrical. Radial cleavage pattern. Triploblastic. Internal Skeletons. Coelomates.
Blastopore
a depression formed when cells of the blastula move inward and becomes the mouth in protostomes and the anus in deuterostomes
diploblastic
two cell layers (ectoderm, endoderm)
triploblastic
three cell layers (ectoderm, endoderm and mesoderm)
Spiral Cleavage
Not perfect cleavage everything random
Radial cleavage
90 degrees to the preceding division
Asymmetrical organism
no plane of symmetry
Spherical symmetry
divided along an infinite number of planes
Radial symmetry
one main axis around which it's body parts are organized, divided along the plane that contains the main axis (jelly fish)
Bilaterally symmetrical
divided into mirror images by a single plane that passes through the dorsoventral midline (frogs, people)
cephalization
concentration of sense organs and nerve cells at the front of an animal's body (advantageous because the front feels out a new environment first)
Acoleomate
Lack an enclosed fluid filled body cavity has mesenchyme
Mesenchyme
mesh of carbohydrates and lipids where the body cavity would be
Pseudocoelomate
Body cavity is called a pseudocoel, enclosed by a muscle only on its outside
Coleomate
Have a coelem that develops with in the mesoderm. The peritoneum (mesoderm- muscle) surrounds the internal organs and there is fluid between the layers.
Coelem
fluid-filled body cavity lined with mesoderm
Segmentation
Better movement control, specialization of different body regions
Appendages
better locomotion, move faster through the environment
Sessile
adhere themselves to an object and stay there (they have cells that move though)
Motile
animals that move around to get their food
Filter feeders
Air and water contain small organisms and organic molecules they live off of, filter feeders can be sessile or motile
herbivores
generally many types of herbivores feed on the same plant, they must expend energy to digest the plant material
Predators
capture and subdue large prey, have highly developed sensory organs and have toxins (jellyfish)
Cnidocyte
a stinging cell of a cnidarian
nematocyst
stinging structure within each cnidocyte of a cnidarian that is used to poison or kill prey
Omnivores
Eat both plants and animals
Parasites
live in or on another organism, obtain nutrients by consuming parts of the organism or use the food the organism is taking in
Ectoparasites
are external parasites, they live on thier host and do not enter the body
Endoparasites
internal parasites that live inside the host's body
Life cycle
The embryonic development, birth, growth to maturity, reproduction, and death.
Direct development
born as a mini adult (humans)
Indirect development
starts out as a larva, and then changes to become adult shaped
metamorphosis
the marked transformation of a larva into an adult
Dispersal stage
movement of organisms from a parent organism (and or point of origin)
Parasitic life style
maximize dispersal to overcome host defenses
Trade-offs
no life cycle maximizes all benefits, Organisms where their offspring that may not make it to adult hood produce a ton of eggs, birds where they have further development in the egg but there is also a ton of energy put into keeping that egg safe. So they don't have too many.
Porifera
Sponges, sessile, have spicules, a water canal system, osculum and choanocytes, they do not have tissues, they are a loose organization of cells that live close together, asymmetrical
Spicules
they make up the supporting skeleton of the sponge
Water canal system
a system that constantly moves water through the pores, the water goes into the central pore and out the osculum
Osculum
A large opening on a sponge through which filtered water is expelled
Choanocytes
Feeding cells (pick up small organisms that are in the water moved by the flagella through the canal system)
Sponge diversity
they range in size from small to big, they have different materials, some are carnivorous and most are marine, only 50 species are freshwater
Ctenophora
Comb jellies (not jellyfish) they have a complete gut, ctenes, feeding tentacles, and have radial symmetry
Ctenes
Comb like rows of fused plates of cilia, use for movement
Feeding tentacles
small hairs that secrete a sticky environment so that organisms attach to them
Cnidaria
Diploblastic, blind gut, predators, radial symmetry (jellyfish anemones, corals)
Blind gut
only one opening
Complete gut
separate mouth and anus
Polyp stage of Cnidarians
Sessile, mouth and anus are surrounded by tentacles, reproduce asexually by budding, form colonies
Medusa stage of Cnidarians
free swimming, shaped like a bell, floats with mouth and tentacles facing down, reproduce sexually (release sperm and eggs into surrounding water)
Planula larva
larva of medusa stage, they are free swimming and eventually settle to the bottom and become a polyp
Anthozoa
No medusa stage, includes sea anemones (solitary) and corals (sessile and colonial)
Corals
Sessile and colonial, Skeleton of calcium carbonate, Photosynthetic dinoflagellates
Photosynthetic dinoflagellates
live in the cells of each coral polyp, produce sugars used by the polyps and provide at least half of the energy used by the coral animals.
Hydrozoa
Polyp is dominate stage and are specialized, they are colonial
Scyphozoa
Jelly fish! Medusa is dominate stage, thick mesoglea, polyp produces medusa by budding
yunnanozoans
ancestral deuterosomes because a large number of fossils of these were found on the yuccan province of china, They had external gills, a large mouth and the abdomen appeared to be covered with a cuticle
Echinoderm
Pentaradial Symmetry, complete digestive system, bilaterally symmetrical larve, internal skeleton, water vascular system
Pentaradial symmetry
circular body plan that can be divided into 5 equal parts
Water vascular system
system of fluid-filled tubes used by echinoderms in locomotion and feeding and respiration
Chordates
Dorsal, hollow nerve cord, a tail that extends beyond the anus, notochord
notochord
dorsal supporting rod that is flexible and made of gelatinous material that serves as support
lancelets
maintain all chordate features as adults
urochordates
pharyngeal baskets
pharyngeal baskets
a structure of urochordata where water is filtered
Vertebrates
Vertebral column, rigid internal skeleton, two pairs of appendages, anterior skull with enlarged brain, internal organs suspended in coelum, well developed circulatory system
Jawless fishes
hagfish and lampreys, cartilaginous skeleton, feed on dead and living organisms, freshwater and marine
Jaws
evolved from gill arches, grasping, chewing, increased variety
Chondrichthyans
sharks/rays; cartilage skeleton; suspension feeders/predators; have jaws, but not lobed fins
Ray-finned fishes
bony skeletons, swim bladders
swim bladder
an air-filled sac near the spinal column in many fishes that helps maintain buoyancy
Sarcopterygians
(lobe-finned fish)--includes tetrapods, lungfish (Dipnoi), and coelacanths (Actinistia)
Lobe-finned fishes
jointed fins, able to move to land, waddle
Lung fishes
lung like structures, able to breathe air temporarily, dried up water beds
Tetrapods go to land
Jointed fins evolved to walking legs. Organisms used terrestrial food sources, and became tetrapods (reptiles, birds, mammals)
Amphibians
invaded land, small lungs, confined to moist environment, 3 chambered heart, reproduction requires water
Amniotes Colonized dry land
Evolution of an egg that is impermeable to water. Got a tough skin and kidneys that excrete a concentrated urine.
Reptiles
Covered with horny scales, use lungs for gas exchange, heart dividd into chambers for higher pressures and activity levels
Dinosaurs
Lived on earth for 150 million years, terrestrial, some on two legs which allowed for faster movement because of the pressure taken off the lungs. development of muscles that allowed them to run and breathe at the same time
Birds
Descedents of Dinosaurs, have feathers, and divided into flightless and fliers
Archaeopteryx
extinct primitive toothed bird of the Jurassic period having a long feathered tail, wings, wishbone, and hollow bones (what modern birds are descendants of)
Feathers
Are unique to birds, used for heat regulation, and flight wings provide warmth
Mammels
Small ones coexisted with dinos, sweat glands, mammary glands, have hair, a four chambered heart and eggs that are fertilized internally
Prototherians
lack a placenta, lay eggs, and have sprawling (short) legs
Therians
Marsupials and Eutherians
Marsupials
Mammals whose immature offspring complete their development in an external pouch, have a pseudoplacenta and a short gestation period.
Eutherians
Young are more highly developed at birth, have a placenta (amniotic egg internalized) (More common)
Primates
Dextrous hands, nails not claws, forward facing eyes, small number of offspring
Dextrous hands
opposable thumbs and can rotate their hands
Prosimians
Arboreal (tree living) nocturnal primates
Anthropoids
New world and old world and awake during the day, includes apes
New world Anthropoids
Arboreal, prehensile tail
Old world Anthropoids
Arboreal, terrestrial, no prehensile tail, we evolved from them
Hominids
Separated 6mya in africa, Ardipithecines, Bipedalism, Australopithecines
Ardipithecines
the earliest protohominids
Bipedalism
frees the forelimbs, elevates the eyes, requires less energy
Australopithecines
Any of several extinct humanlike primates that lived from about 4 million years ago to 750,000 years ago. The name means "southern ape", which refers to the area in Africa where they were primarily found. The most famous of the fossil remains was given the nickname of Lucy.
Homo erectus
first to use tools and create a culture
Homo neanderthalensis
suddenly disappeared, most likely homo sapiens took over their land and killed them off
Lophotrochozoans
internal skeleton, free swimming larva stage, lophophore used for feeding, spiral cleavage (flatworms, rotifers, annelids)
Flatworms
Bilateral symmetry, acoelomates, oxygen exchange takes place outside the body, digestive cavity is highly branched, free living or parasitic
Rotifers
Pseudocoelomates, very tiny, complete gut, cillia for movement, specialized food collecting organs
mastax
muscluar organ that breaks the food into smaller particles in a rotifer
corona
mouth of a rotifer
Annelids
Segmented bodies allow for improved motor control, coelom in each segment, ganglia. Soft body covering is good for gas exchange but not for retaining water. They can be marine, freshwater or terrestrial.
Ganglia
concentration of nerve cells
Mollusks
Snails, clams, chitons, octopus, squid. 3 part body plan, the foot is used for movement, the visceral mass consists of all internal organs and the mantle protects the internal organs and secretes the shell. The mantle cavity contains the gills.
Gastropods
snails and conches belong to the class of mollusks
Bivalves
mollusks that have two shells held together by hinges and strong muscles, clams. Siphons pull in water and push back out the other siphon to keep gills moist. The foot is a digging tool to bury themselves.
Cephalopods
squid, octopus, nautilus. Foot is a tentacle used for movement and for grabbing food.
Ecdysozoans
Animals that have an exoskeleton that is a thick non living covering. It provides protection and support, it does not grow with the organism. Some exoskeletons contain chitin and the exoskeleton allows for new mechanisms for locomotion and respiration.
Molting
process in which an arthropod sheds its exoskeleton and manufactures a larger one to take its place
Cuticle
Thin exoskeleton, protects the animal but does not provide support, hydrostatic skeleton, allows for the exchange of gases, minerals and water.
Nematodes
Roundworms, pseudocoelom, multilayered cuticle, has a pharynx, uses sexual reproduction, lives in almost every habitat on Earth.
Pharynx
pumps food through their digestive tract
Arthropods
Exoskeletons contain chitin, segmented bodies and thick rigid exoskeletons, coelomates, jointed appendages, first to invade land (preserved water)
Relatives of the Arthropods
Onychophorans and Tardigrades, flexible cuticle, unjointed appendages, hydrostatic skeleton for movement.
Trilobites
Jointed legs (some modified for specific functions), Became extinct after paleozoic era, heavily armored.
Myriapods
2 body regions (head and trunk), centipedes (predators) and millipedes (scavengers)
Chelicerates
Bodies have 2 regions (anterior, posterior), 4 pairs of walking legs, 3 classes (pycnogondia, merostomata, arachnida)
Arachnids
Terrestrial, simple life cycle
Crustaceans
Marine arthropods, body with three regions (head, thorax, abdomen), carapace.
Carapace
hard outer covering or case of certain organisms such as arthropods and turtles
pycnogondia
Class of Chelicerata: SEA SPIDERS
merostomata
(Horseshoe Crabs) Shelled with soft belly, and have many spikey areas, external fertilization
Insects
Hexapods, terrestrial and freshwater, 3 body parts (head thorax and abdomen), tracheal system, spiracles
Tracheal system
A gas exchange system of branched, chitin-lined tubes that infiltrate the body and carry oxygen directly to cells in insects.
Spiracles
breathing tubes of insects located on abdomen
Apterygotes
Wingless insects, hatch looking like miniature adults, springtails and silverfish
Pterygotes
winged insects that all undergo incomplete metamorphosis
Physiology
The study of how organisms work, the study of the functions of all of the parts and processes, understanding how organisms live in different environments.
Homeostasis
Maintenance of constant conditions in the internal environment. Direct exchange with the environment (environment provides nutrients, lifestyle is limiting). Cells of multicellular organisms exist within an internal environment. (ECT, cell specialization, organ systems)
ECF
Extracellular fluid - cells are bathed in it
Why Direct exchange is limiting?
All parts of the organism can only be a few cell layers thick, every cell must be independent, environment must provide all of its cellular needs.
Regulation
the act of controlling
Set points
the desired level at which you want something to function
Feed back
the measure of where you are in relation to a set point
Positive feedback
Amplifies a response
Negative feedback
Causes the effectors to reduce or reverse the process that created the signal (once you've deviated back to normal)
Feed forward
the type of information that changes the set point
Physiological regulation
Effectors, controlled systems, regulatory systems
Effectors
cells, tissues and organs, they cause the change to take place
Controlled systems
systems in which their activities are controlled by commands from regulatory
Regulatory systems
receive, process and integrate information in order to issue commands to the controlled system (nervous system and endocrine system)
Sensors
sensitive devices that respond to changes in the environment
Tissues
An assemblage of cells. (epithelial, connective, muscle, nervous) Organs are composed of tissues.
Epithelial tissue
lining, transport, secretion, absorption. Sheets of tightly packed cells, cover inner and outer surfaces of the body. Acts as a barrier. Lines hollow organs.
Connective tissue
Loosely packed cells dispersed in an extracellular matrix. Composition and properties of the matrix differ. Components are collagen, elastin, proteoglycan. Support, strength and elasticity
Muscle tissue
Consists of cells that an contract, most abundant tissues in the body 3 types
nervous tissue
information synthesis, communication, control. Processes information, controls other organ systems, 2 types of cells.
Squamus epithelial tissue cells
flattened, structural function, outer layer of the skin, permeability barriers
Cuboidal or columnar epithelial tissue cells
involved in transport or secretory functions, lots of organelles
Simple Epithelium
single layer of cells (form tubules of the kidneys)
Stratified epithelium
multiple layers of cells (skin)
Pseudostratified epithelium
single layer of cells, but the cells are of different sizes and give appearance of being stratified (tissue lining the respiratory tract)
Skeletal muscle
connects one bone to another
Smooth muscle
found in the internal organs, not under voluntary control, constricting blood moving food through the gut
Cardiac muscle
found only in the heart, pumps the blood
Extracellular matrix
loosely packed cells dispersed throughout extracellular matrix. Extracellular proteins are collagen elastin and proteoglycan.
Collagen
25% of total body protein, gives tendon and skin their resistance to stretch, netlike framework for organs giving them shape and structural strength
elastin
stretchable protein, can be stretched several times its resting length. Lungs and large arteries. Skin snaps back due to these fibers and loss of these with age causes loss of resiliency.
Proteoglycans
give connective tissues resistance to compression, connective tissues lining the joints.
Cartilage
collagen fibers embedded in a flexible matrix consisting of chondroitin sulfate, chondrocytes are the cells forming the cartilage, skeletons of early developmental stage
Bone
harder than cartilage, adult vertebrates maintain cartilage in the outer ear and the nose bone is hardened by the deposition of calcium phosphate
Adipose tissue
stores fat, cushions organs, prevents heat loss, stores energy
Blood
cells are dispersed in an extensive extracellular matrix called plasma, contains a lot of proteins such as fibrinogen - serves in blood clotting
Neurons
generate the electrochemical signals, control most organ systems to maintain homeostasis
Glial cells
support the neurons, provide nourishment, outnumber the neurons
Effect on internal temperature
The environment can effect it.
Cells upper limit
45 degrees Celsius
Cells lower limit
0 degrees Celsius
Temperature Sensitivity
Physiological reactions are sensitive to change in temperature. Every reaction has an optimal temperature.
Q10
Q10=2 For every 10 degree increase in temperature you double reaction rate. Q10=3 For every 10 degree increase in temperature you triple reaction rate.
Ectotherms
Regulate body temp. using external heat sources.
Endotherms
Regulate body temp. by producing heat metabolically or by activating heat loss mechanisms.
Heterotherms
Behaves as both an ectotherm and an endotherms.
Radiation
We lose heat and absorb heat from the environment.
Evaporation
specific heat of water helps (high specific heat) which takes a lot of input to get it from liquid to gas so it pulls a lot of heat out of the body to do that
Convection
breeze
Cold fish
Active fish produce a lot of metabolic heat, but have a hard time retaining that heat.
1. The heart pumps blood to the gills where it becomes oxygenated the blood cools to water temperature while in the gills because it is near the surface
2. This cold water flows through the center of the fish in the large dorsal aorta.
3. Arteries then carry the blood to the tissues and veins return it to the heart.
Hot fish
1. The central aorta is much smaller.
2. Most of the blood is transported in vessels that are just under the skin. The "cold" blood is then transported in to the muscle mass by smaller vessels that are deeper in the muscles.
3. The arteries carrying the blood to the tissues run parallel and in close contact with the veins that are returning the blood to the heart.
4. The warm blood that is returning to the heart warms the blood being carried to the tissues
The Countercurrent Heat Exchanger
blood flows in opposite directions
Flying insects
Have to warm up flight muscles. before flying, especially in cold temperatures, these insects will warm their wings by contracting the flight muscles in a manner that is similar to shivering.
Honeybees
Regulate temperature as a group
Thermoneutral zone
Metabolic rate is low and independent.
Basal metabolic rate
The metabolic rate of an animal at rest.
nonshivering heat production
occurs in brown fat - protein called thermogenin uncouples proton movement from ATP production - brown fat is found in newborn infants and in some adult mammals that live in cold climates or that hibernate
Adaptations to the cold
Animals have rounder bodies and shorter limbs, decreased blood flow to the skin, increased thermal insulation, fur and feathers, humans add clothing.
Heat loss through evaporation
Water increases the rate of heat loss, animals can sweat or pant to cool the body, must use energy to pant or sweat - produces heat
Vertebrate Thermostat
Located in the hypothalamus, uses the feedback information, when temperature drops it triggers responses for decreasing heat loss.
Hypothalamus
Establishes a set point.
Feedback information
Hypothalamus temperature, skin temperature, environmental temperature
Hormones
Chemical signals that have effects on cells in other parts of the body. Control long term developmental processes. Released by endocrine cells and bind to target cells. Can have different effects on different types of cells.
Target cells
have receptors for a hormone
Chemical signaling systems
Endocrine glands, exocrine glands, neurotransmitters, pheromones
Endocrine Glands (signaling)
secrete hormones into the extracellular fluid
Exocrine glands (signaling)
have ducts that carry hormones to the surface of skin or into a body cavity
Neurotransmitters (signaling)
Chemical signals released by neurons. Used for communication between neurons
Pheromones (signaling)
Chemical signals released by animals into the environment. Can be used for communication by animals. Mate attraction.
Hormonal Control of Molting
Insects undergo many molts during development. Sir Vincent Wigglesworth did experiments on it.
Sir Vincent Wigglesworth
Use the bloodsucking bug Rhodnius prolixus for experiments on molting. Hypothesized that molting was triggered by a chemical signal.
Circulatory hormones
released somewhere in the blood stream and carried to somewhere else
Paracrine Hormones
Doesn't enter the bloodstream but binds to receptors in the general area where it was released.
Autocrine Hormones
Binds to receptors on the cell that released it. The function is to control its own release.
Prothoracicotropic Hormone (PTTH)
"Brain hormone". Produced by brain cells and stored in the corpora cardiaca. Released after the blood meal. Stimulates the release of ecdysone.
Ecdysone
Produced in the prothoracic gland. Stimulates molting.
Juvenile Hormone
Controls development in juveniles. Prevents maturation. Located in the corpora allata (back portion of the head).
Instar
growth stage between two molts
Rhodnius prolixus
Molts 5 times during development. Molt is triggered by a blood meal but the signal takes time to get from the head to body. When decapitated they go straight to adult.
Peptide hormones
Water soluble, easy transport in the blood. Such as Insulin.
Steroid hormones
Derivatives of cholesterol (lipid soluble). Testosterone, estrogen.
Amine hormones
Derivatives of amino acid tyrosine (may or may not be water soluble). Thyroxin.
Hormone receptors
Can be on the inside or outside of cells. A target cell has to have a receptor.
Lipid-soluble hormones
Receptors on the inside of cell. Many effect gene expression.
Water-soluble hormones
Receptors on the cell surface. Binding domain (binds to the hormone) transmembrane domain (goes into the cell) cytoplasmic domain (activates something.
Epinephrine
Released by the adrenal gland. Helps us respond to something dangerous. Binds to receptors in the heart and blood vessels. Constricts blood vessels in digestive tract. Liver cells - increase glucose. Fat cells - release energy.
The pituitary gland
"The master gland" is attached to the hypothalamus. 2 parts Posterior and anterior pituitary.
posterior pituitary
Releases 2 neurohormones called antidiruetic hormone and oxytoxin they are carried to posterior pituitary in vesicles down the pituitary stalk.
anterior pituitary
Releases tropic hormones and hormones that act directly on non endocrine tissues. Controlled by neurohormones (releasing hormones) but connected by portal blood vessels.
pineal gland
produces hormones used in biorhythms.
thymus gland
t cell formation hormone
Neurohormones
produced by neurons in the hypothalamus, travel down axon and into blood stream
Tropic hormone
Produced in anterior pituitary. Control the actions of other endocrine glands. (Thyrotropin, corticotropin, luteinizing hormone and follicle-stimulating hormone)
Hormones that act directly on nonendocrine tissues
Produced in anterior pituitary: Growth Hormones Prolactin Endorphines and enkephalins (pain receptors - runners high)
Negative feedback loop
when the amount of a particular hormone in the blood reaches a certain level, the endocrine system sends signals that stops the release of that hormone
Releasing hormones
hormone released by the hypothalamus that flows through the blood to the anterior pituitary, to control the release of it's hormones
Portal blood vessels
connect the hypothalamus and anterior pituitary
Thyrotropin releasing hormone
signals the anterior pituitary to release TSH (thyroid stimulating hormone)
Gonadotropin releasing hormone
this hormone stimulates the anterior pituitary to secrete FSH and LH
Genome
The full set of genes plus noncoding regions of DNA. Eukaryotes = most on the chromosomes (also in mitochondria and chloroplasts). Virus = RNA
Mutations
raw material for evolutionary change and if it leads to a phenotype that's advantageous then it will be selected for.
Molecular Evolution
Investigates the mechanisms and consequences of the evolution of macromolecules. Study relationships between gene and proteins, DNA, RNA. Genes can evolve by nucleotide substitutions. Changes in amino acid sequences.
DNA made up of
Nucleotides
Proteins made up of
Amino acids
Evolutionary change
Identified by comparing nucleotide or amino acid sequences from different organisms. Determines when and why changes occurred. Reconstructs the evolutionary history of groups of organisms.
Sequence alignment technique
deletions and insertions in the sequence are determined by adding gaps and aligning sequences
Similarity matrix
-gives us a measure of the minimum number of changes that have occurred
-which positions are most variable or most stable
Multiple substitutions
More than one change at a given position
coincident substitutions
different substitutions in different descendants
parallel substituions
same substitution in different descendants
reversion
one change at a position is changed back to the original
Sequence comparison
may not give us the whole story, the database of sequences is continuously expanding. Databases have been constructed for homologous proteins.
Data for cytochrome c sequences have been aligned for a variety of species.
Cytochrome c
protein thats involved in the electron chain
How to study evolution in the lab
Use unicellular organisms or virus b/c
- short generation time
- high substitution rate b/c short time and no DNA proofreading
uniform environment
does not lead to morphological diversification
heterogenous environment
phenotypic change and diversification are enhanced
Silent mutations
do not change amino acid sequence
missense mutations
do change amino acid sequence
Pseudogene
duplicate copy of gene that is no longer functional - high rate of these substitutions
Genome size
Varies among organisms. Correlation between organism complexity and genome size but not always true.
Non coding DNA
- may have no function
- alteration of gene expression
- pseudogenes
- maintenance of chromosome structure
-transposable elements (sequences that move from gene to gene)
Genome growth
gene transfer, or duplication
Lateral gene transfer
Individual genes move from one lineage to another, from the environment or hybridization, can be advantageous
Bacteria lateral gene transfer
Bacteria can pick up plasmids which they used to create antibacterial resistance
Endosymbiosis
Process through which early prokaryotic cells are thought to have engulfed other, smaller cells and eventually incorporated them as organelles; these cells evolved into modern-day eukaryotes
Gene duplication
- may retain original function
- may retain but expression time is different
- pseudogene
- new function
Gene families
result from many successive rounds of duplication
Gene tree
shows evolutionary relationships of a single gene in different species
invitro evolution
new molecules produced in a lab
Coccus
spherical bacteria
bacillus
rodshaped bacteria
helix
curved shaped bacteria
Biofilms
many different cells, difficult to kill once it forms. Prokaryotes secrete a sticky matrix which they stick on and grow together
Prokaryotes can
live anywhere and adapt to anything
Old faithful
blue cyanobacteria
Prokaryotes & Eukaryotes can
Conduct glycolysis
Semi conservative dna
dna encodes proteins
transcription & translation
plasma membranes and ribosome
Transcription
DNA to RNA
Translation
RNA to protein
Ribosome
maker of proteins
Semi conservative
two strands that are bound to one another and one is a copy one is coded
Differences of Prokaryotes
Reproduction by binary fission. Circular DNA (one chromosome). Plasmids can give anti bacterial resistance. Do not have organelles.
Binary Fission
a form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size
Differences of Eukaryotes
have their genome along more than one chromosome. have little compartments that carry out specific functions
Peptidoglycan
Unique to bacterial cell walls , good target for antibiotics eukaryotes dont have them
Gram staining
A process by which components of bacterial cell walls are bound to Gram's stain. Depending on the amount of peptidoglycan in their cell walls, bacteria stain differently and are classified as Gram-negative or Gram-positive.
Gram positive
bacteria that retains purple stain inside the cell wall during the Gram staining procedure
gram negative
bacteria with a more porous cell wall, does not retain purple stain, appears red/pink/orange after Gram straining procedure
Movement
Gliding, flagella, corkscrew motion, gas vacuoles
Asexual reproduction
short generation time, little chance of mutation but because the short generation time there can be, our immune system can't keep up
Density sensing technique
they can tell how many there are of each other
bioluminescence
the production of light by means of a chemical reaction in an organism (ocean and land) and they attract each other
Obligate anaerobes
oxygen is toxic
Facultative anaerobes
can use the oxygen when it is present
Aerotolerant anaerobes
use anaerobic metabolism but can tolerate oxygen
Obligate aerobes
can't survive without oxygen
photoautotrophs
photosynthetic prokaryotic organisms that harness light energy to drive the synthesis of organic compounds from CO2
photoheterotrophs
an organism that obtains energy from light but must obtain its carbon from organic compounds from other organisms
chemolithotrophs
organisms that obtain energy from the oxidation of inorganic compounds and then fix CO2 (take the carbon from CO2)
Chemoheterotrophs
use organic compounds for energy to fix carbon
spirochetes
parasites, pathogens, free living bacteria
chlamydias
smallest bacteria, parasites, eye infections, stds
Cyanobacteria
blue green, photosynthisizers, pond scum, believed to have become chloroplast first
proteobacteria
largest group of described bacteria, mitochondria origins, live freely or in a population
Archaea
no peptidoglycan, unique cell membrane lipids, extremophiles
thermophiles
very hot
halophiles
high salt
acidophiles
acidic
methanogens
methane gas is used to fuel their metabolism
virus
not cellular, depend on other organisms, have a protein shell with DNA or RNA and function by entering another cell, same genetic storage and transfer as organisms, and they replicate mutate and evolve
Eukaryotes evolved
loss of the cell wall, cell surface became flexible, cytoskeleton formed, nuclear envelope formed, appearance of digestive vacuoles, acquisition of organelles
Cytoskeleton
internal mesh of proteins that gives the cell structure
Nuclear Envelope
Membrane around DNA
Protists
Eukaryotes that are not plants or animals or fungi
Endosymbionts
a condition in which two organisms live together, one inside the other , they live inside other things like coral (protists do)
Plants
Came from most likely green algae, developed from an embryo protected by parent tissues, Cellulose in cell walls, chloroplasts use chlorophylls a&b, use starch as a major energy storage carbohydrate
Plant adaptation
appeared 400 to 500 million years ago and they needed a way to transport water to all parts of the plant, structural support and methods to disperse gametes
Waxy Cuticle
covering that slows water loss
Stomata in the leaves
Openings in stems and leaves, regulates gas exchange
Gametangia
enclose and protect gametes from drying out
Embryos
contained in a protective structure
spores
reproductive particle
pigments
provide protection against uv radiation
Mutual association with
fungus
Life Cycle
Includes a multicellular diploid and a multicellular haploid stage.
Gametes
produced by mitosis
Meiosis
produces spores that develop into haploid organisms
Sporophyte
multicellular diploid plant, produces spores in the sporangia by meiosis, spores develop into a haploid plant
Gameotophyte
multicellular haploid plant, produces gametes by mitosis, gametes fuse during fertilization to produce the diploid sporophyte embryo
Gametophyte generation
non vascular
soporophyte generation
vascular
non vascular plant
liverworts, mosses, hornworts, have a thin cuticle and grow in moist environments in dense mats, lack leaves stems and roots
Xylem
(vascular plants) Conducts water and minerals from soil up to the rest of the plant, cell walls contain lignin
Phloem
conducts products of photosynthesis throughout the plant
Tracheid
specialized cell
Branching sporophyte
not dependent on the gametophyte
heterospory
two types of spores develop into separate male and female gametophytes, all seed plants
Wood stems
proliferation of xylem, called secondary growth
Gymnosperms
pines and cycads
Angiospersms
flowering plants
Megasporangia
female gametophyte
Microsporangia
male gametophyte
Seed
may remain viable for years, germinate when conditions are favorable, seed coat prevents drying and provides protection
Naked seeded plants
Ovules and seeds are not protected by ovary or fruit tissue, conifers
Double fertilization (angiosperms)
2 male gametophytes: one combines with the egg, one combines with the other cells and will form the endosperm
Stamens
bear microsporangia, filament and anther
carpels
bear megasporangia, one or more carpels form the pistil, stigma, style and ovary
petals
corolla
sepals
calyx
Pollination
Everything in flowers are modified leafs. Pistal is where the mega gametophyte is located. Surface is called the stigma, the stalk is called the style, then the ovary and ovule. The stamen has the anther on top and that holds the pollen grains. When fertilization takes place theres a formation of a pollen tube, that the pollen grain can move down, one fertilized an egg and one fertilizes the endo spore, which provides nourishment for the seed.
Perfect flowers
have both mega and microsporangia
Imperfect flowers
either mega OR micro
monoecious
male and female flowers occur on the same plant
Dioecious
male and female have separate flowers
Inflorescence
many flowers grouped together
Fruits
ovary and seed develop
absorptive heterotrophy
secrete digestive enzymes outside the body to break down large food molecules, then absorb the products
saprobes
absorb nutrients from dead organic matter
parasites
absorb nutrients from living hosts
mutualists
both partners benifit
Fungi
evolved from a unicellular protist with a flagellum
Choanoflagellates
ancestor of fungi and animals
Distinguishing Fungi
Absorptive heterotrophy and chitin in cell walls
Yeasts
Unicellular members of zygomycetes, sac fungi and club fungi, refers to a lifestyle that has evolved multiple times
mycelium
body
hyphae
tubular filaments, the cell walls have chitin can reorganize to form a fruit body such as a mushroom
septa
incomplete cell walls
coenocytic
hyphae without cell walls
Rhizoids
modified hyphae for anchoring
Fungal reproduction
asexual or sexual reproduction
asexual reproduction
more common, production of haploid spores in sporangia, production of spoes at hyphae tips, cell division by unicellular fungi, breakage of the mycelium
sexual reproduction
classified into mating types, hyphae of differnt types meet and fuse
Saprobic fungi
major decomposer
pathogenic fungi
major cause of death in people with AIDS
Symbiotic relationships
partners live in close permanent contact
mutualisitc
both benefit, mycorrhizae, relationship between fungi and plant
Lichens
live in some of the harshest environments on earth, get carbon from photosynthetic cells, hyphae provide nutrients
Micorrhizae
provides additional surface area for water absorption from the soil
Sac
marine, freshwater, terrestrial, asci (sac) yeasts, molds
Club
mushroom puff bracket
Glycolysis
convert glucose to 2 pyruvate
Biology
Study of life.
Organisms
Living things have one or more cells genetic info carbon, nitrogen etc. All the organisms descended from a common single-celled ancestors. They are all related to the first organsim that evolved.
Characteristics Shared by Most "living things"
Consist of one or more cells.
Contain genetic information. Capable of reproduction. Are genetically related and have evolved. Capable of metabolism. Capable of homeostasis.
Evolution
A central theme in biology. Living systems evolve though differential survival and reproduction. Evolution has generated diversity on earth.
Adaptations
Characteristics and processes that help an organism survive better than other organisms.
Fossil record
Structures that have been fossilized and compared to others to show evolution.
History of life on earth
Earth formed 4.5/.6 billion years ago. 600 million years before life started to evolve.
Chemical Evolution
Small molecules came together to form larger ones that could store information. Which eventually became cells.
Photosynthesis
Changed earth's atmosphere by adding oxygen which allowed prokaryotes to use the sun to fuel themselves.
Eukaryotic cells
Evolved to have small compartments that provide functions that have a nucleus. Eventually organisms became multicellular.
Cell specialization
Compartmentalized certain cells could only do specific function and they had different structures.
Domains
bacteria, archea, eukarya
The scientific method
A process of using common sense and logic to solve a problem. There are 5 steps. 1) observation. 2) Ask Questions 3) Formulate a Hypothesis 4) Make Predictions 5) Test the hypothesis.
Controlled experiments
Laboratory, everything is controlled but one variable
Comparative experiments
Scientists make predictions about patterns that should exist in nature.
Evolutionary Theory
The understanding and application of the mechanisms of evolutionary change to biological problems. Helps develop vaccines, develop better crops and understand the diversification of life.
Theory
An entire body of work on the understanding and application of a field of knowledge.
Charles Darwin
Interested in geology and natural science. Studying to be a clergyman. Worked on the Beagle as a naturalist to collect specimen, map currents and formulate ideas.
Darwin's Studies
South American species were different from European species. Species of the galapagos islands were different on each island.
Darwin's theory
Species change over time, similar species share a common ancestor, the mechanism that produces change is natural selection.
Thomas Malthus
Populations have the potential for rapid increase but they do not get out of control because death rates are high and there is a limit to the size of a population by lack of food, shelter, predators and illness.
Artificial selection
Breeders and crop growers select for desirable traits.
Population
A group of individuals of the same species that live and interbreed in a particular geographic area. Members of a population become adapted to the environment in which they life. For a population to evolve its members must posses heritable genetic variation.
Adaptations
The processes by which useful characteristics evolve. Also: the characteristics themselves.
Phenotype
the physical expression of an organisms genes. Eye color, height.
Trait
Specific form of a phenotype. Blue eyes.
Heritable trait
traits that have a genetic input
genotype
the genetic makeup of a character
Allele
the different forms of a gene
The gene pool
consists of alleles and they are the source of genetic variation
Evolutionary mechanisms of change
Mutation, gene flow, genetic drift, nonrandom mating, natural selection
Mutation
Any change in the nucleotide sequences of DNA. Create and help maintain genetic variation. Occurs randomly with respect to the adaptive needs of an organism. Most are harmful or neutral and mutation rates are generally low.
Gene flow
Most populations are not completely isolated. It is a result of the migration of individuals between populations. Alleles may be added to the gene pool and allele frequencies may change.
Genetic drift
Random changes in allele frequencies from generation to generation.
Population bottleneck
A situation in which the size of the population is drastically reduced. Can lead to a decrease in genetic variation.
Founder Effect
Results from colonization of a new region, they start a small population somewhere else so there is a decrease from their older, larger population.
Nonrandom mating
Individuals choose mates with specific characteristics. Can alter genotype frequencies. Self-fertilization. Sexual selection.
Sexual selection
Results in evolution of significant differences between male and females. Selected for specific traits which are seen in the next generation.
Variation
The result of mutation. Natural selection acts on the phenotype not the genotype.
Fitness
The contribution of a phenotype to the survival of new generations. The allele has high fitness when it give the population advantage to the increase.
Stabilizing selection
Maintains the average characteristics of a population
Directional selection
Favors individuals that vary in one direction from the average.
Disruptive selection
Favors individuals that vary in both directions from the mean.
Sexual Recombination
New combinations of genes. Permits the elimination of detrimental mutations. Generates new allele combinations on which natural selection can act.
Constraints of evolution
If an allele does not exist that trait will not evolve. Must work within the boundaries of universal constraints. Cells must remain small. Protein folding. Laws of thermodynamics.
Developmental processes
Constrain evolution. All evolutionary innovations are modifications of previously existing structures.
Trade offs
Constrain evolution. Adaptations can impose. Some snakes became TTX resistant but the TTX resistant snakes are slower than the non resistant ones.
Species
Groups of organisms that mate with one another. Many species are recognized by their appearance.
Lineage species concept
each species has a history that starts with a speciation event & ends either at extinction or another speciation event
Speciation
the formation of new species as a result of evolution
Biological species concept
definition of a species as a population or group of populations whose members can breed with one another in nature and produce fertile offspring. Groups of interbreeding populations that are reproductively isolated from other such groups.
Dobzhansky-Muller Model
is a model of the evolution of genetic incompatibility. It assumes a selective pressure against a combination of alleles in the heterozygous state, hybrids have reduced fertility or viability. The end result of this evolved incompatibility is divergence into separate species.
Allopatric speciation
The formation of a new species as a result of an ancestral population's becoming isolated by a geographic barrier. Most common form of speciation.
Sympatric speciation
formation of a new species within the same geographic area
Polyploidy
condition in which an organism has extra sets of chromosomes
Prezygotic reproductive barriers
Impede mating or hinder fertilization so zygotes are not produced. Habitat, behavioral, temporal, mechanical, and gametic isolation.
Postzygotic reproductive barriers
A reproductive barrier that prevent hybrid zygotes produced by two different species from developing into viable, fertile adults
Habitat isolation
populations live in different habitats and do not meet
Temporal isolation
form of reproductive isolation in which two populations reproduce at different times
Mechanical isolation
mating does not occur due to reproductive parts not fitting together
Behavioral isolation
form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from interbreeding
Gametic isolation
Sperm of one species may not be able to fertilize the eggs of another species
Low hybrid-zygote viability
Hybrid zygotes do not survive as well as normal zygotes
Low hybrid adult viability
Hybrid offspring may simply survive less well than offspring resulting from matings within populations.
Hybrid infertility
hybrid offspring are sterile or have reduced fertility
Hybrid zones
region where different species meet/mate producing hybrid offpsring
Biological evolution
a change over time in the genetic composition of a population
Microevolution
changes that happen during the lifetime of a species
Macroevolution
changes that involve the appearance of new species.
ex. the formation of the human species, formation of vertebrates
Fossils
Remains of ancient organisms preserved in rock.
Nicolaus Steno
The geologist who made the connection between layers of rock and age.
Radioactive isotopes
An isotope of an element with an unstable nucleus.
Half life
The time it takes for 1/2 the isotope to decay to its stable form.
Alfred Wegener
The first to suggest that the continents have moved.
Continental drift
Earth's crust consists of plates floating on a fluid layer of molten rock. The movement of plates.
Cyanobacteria
bacteria that use photosynthesis to create oxygen.
Stromatolites
Structures of dead cyanobacteria.
Increased O2
O2 was initially toxic. Led to the evolution of aerobic metabolism which is more efficient and more energy is gotten in comparison to an anaerobic organism. Lead to evolution of larger eukaryotic cells and multicellular organisms.
Volcanos and life
Many volcanic eruptions has local but not global effects. In the late Permian period, continents collided causing massive volcanic eruptions. Large amounts of ash triggered glaciers.
Meteorite collisions
Large collisions have caused several extinctions, evidence includes disfigured rocks, craters, iridium
Precambrian Period
Lasted more than 3 billion years. Microscopic prokaryotes and eukaryotes. Life existed in the ocean. Massive destruction at the end.
Cambrian Period
Oxygen levels approached current. Huge increase in different species evolving "explosion". Several large continents formed allowing room for evolution.
Paleozoic Era
3 Mass Extinctions. Radiation of marine groups, plants and animals move to lands. The need to internalize watery environment arose. Formation of pangaea (which caused an extinction).
Mesozoic Era
Pangaea begins to seperate. Climate warmed. Oxygen levels rose. Age of dinosaurs. Evolution of mammals. Meteorite collision at the end of era.
Cenozoic Era
Continents moved to current positions. Diversification of mammals. Ice ages. Evolution of hominids ~ 6 million years ago.
Heterotrophs
Eat other organisms to get energy.
Autotrophs
Organisms that use the sun or other sources to make their own energy.
Energy
Energy in the chemical bonds of food is used to make ATP (adenosine triphosphate). It is measured in calories.
Calories
Energy to raise the temperature of one gram of water one degree Celsius. *Food is measured in kilocalories.
Metabolic rate
A measure of the overall energy needs of an animal.
Glycogen
Carbohydrates are stored as glycogen. It is stored in the liver and muscle cells. Glycogen stores last for about a day.
Fat
More energy per gram than glycogen. More compact. Migrating bird store energy in fat or they would be too heavy to fly. Fat can last 4-5 weeks as long as a person is getting water.
Proteins
Not energy storage compounds but if you are in starvation mode (and fat stores are gone) the body will break them down.
Carbon skeletons
Food provides acetyl groups. Used for biosynthesis. Main source is fatty acid molecule which can be used to synthesize proteins, hormones or make other fatty acids.
Amino acids
Building blocks of proteins. (20)
Essential amino acids
Amino acids that animals can't synthesize. (8)
Fatty acids
Animals can synthesize most fatty acids using the acetyl groups acquired from food.
Essential fatty acids
Fatty acids that must be obtained from the diet.
Linoleic Acid
Unsaturated fatty acid. Important in cell membrane, synthesis of steroid hormones and molecules involved in development.
Macronutrients
Minerals needed in large amounts. Calcium.
Calcium (macronutrient)
Bones and teeth, muscle contraction and neuron function.
Micronutrients
Minerals needed in small amounts.
Iron (micronutrient)
Oxygen binding atom in hemoglobin. Most common mineral nutrient deficiency. We lose it when we lose blood and when we lose the walls of our intestines.
Vitamins
Required for growth and metabolism. Most function as coenzymes. Humans require 13. Two types - fat soluble and water soluble.
Fat soluble vitamines
Require fats for absorption and require help through the blood stream.
Water soluble vitamines
Excreted with urine
Vitamin C
Primates can not synthesize, makes collagen, a deficiency leads to scurvy
Vitamin D
A water soluble vitamine but we can synthesize it ourselves. When UV rays hit the skin it synthesizes pre-vitamin D. It is vital to growth. 30-40% of adults are vitamin D deficient.
Saprobes
Decomposers - feed on dead material
Detritivores
Feed on decaying organic material as they go through the soil (earthworms)
Predators
Herbivores - plants
Carnivores - animals
Omnivores - both
Filter feeders
Filter what they eat out of the air and water.
Fluid feeders
Mosquitoes and leaches all live on a fluid diet
Canines
used for gripping and tearing
Incisors
used for cutting
Premolars and molars
used for shredding and grinding
Gastrovascular cavities
Only one opening for digestion
Tubular guts
Two openings: mouth and anus. Food is digested and absorbed throughout from mouth to anus.
Physical break down of food
Teeth, mandibles, gizzard
Storage of food
Stomachs, crops
Lumen
a cavity or passage in a tubular organ
Mucosa
mucus-secreting membrane lining all body cavities or passages that digest
Submucosa
layer under to the mucosa which contains blood vessels, lymph vessels, and nerves
Circular and longitudinal muscles
layers of smooth muscle responsible for the large movements of the gut
Peristalsis
involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system
Swallowing
Pharynx has the an opening for the trachea and esophagus. When food hits the soft palate and the epiglotis they close off the opening to the trachea.
Mouth (chemical digestion)
Amylase - secreted by the salivary glands, starts to break down starch.
Stomach (chemical digestion)
Pepsin - secreted as pepsinogen (gets activated when food is present). Breaks down proteins
HCl
pH of stomach is below 2, converts the pepsinogen to pepsin, aids in the break down of food
Chief cells
Secrete pepsin
Mucus secreting cells
Secrete mucus that protects the walls of the stomach from its own enzymes.
The small intestine
Chemical digestion and absorption. Large surface area, there are folds with a microvila covering which increase surface area.
Chyme
Mixture of gastric juice and partially digested food in to the stomach. Stomach empties slowly into small intestine.
Liver
Secrets bile (stored in the gall bladder). Stores abundant fuel molecules in the form of fat and glycogen. Interconverts fuel molecules. Controls fat metabolism through lipoprotein production. Detoxifies things harmful to the body.
Bile
Emulsifies fat
Pancreas
Releases digestive enzymes: Proteases, amylases, lipases. Releases a bicarbonate to neutralize the chyme.
Absorption of Nutrients
Nutrients are absorbed by the cells of the epithelium. Absorbed nutrients are transported to the liver.
Large intestine
Absorbes water and ions and produces feces.
Epithelial cells
Secrete peptidases, lactase, maltase, and sucrase.
Cellulose digestion
Cellulose is a principal component of herbivore diet. Most are not able to break down cellulose and they rely on microorganisms to break down the cellulose.
Ruminants
have a four chambered stomach; one chamber is called rumen; in the rumen bacteria and other microbes break down cellulose
Gastrin
Released by mucosal cells when food enters the stomach. Stimulates secretion of HCl and pepsin and increases stomach motility.
Cholecystokinin
Released in response to fats and proteins in the chyme. Stimulates the release of bile and pancreatic digestive enzymes.
Secretin
Release stimulated by acid in the chyme. Stimulates the release of bicarbonate from the pancreas to make sure the acidity gets neutralized.
Lipoproteins
A particle made up of fats and cholesterol enclosed in a protein covering. Synthesis takes place in the liver.
HDL's
High density lipoproteins (happy). Removes cholesterol from tissues and brings them back to the liver.
LDL's
Low density lipoproteins. Delivers cholesterol to the cells of the body. Too high is bad and it can create clots and plaque.
VLDLs
Very low density lipoproteins. Transports triglycerides to fat cells and adipose tissue for storage.
Insulin and glucagon
Insulin is secreted when glucose levels are high. Binds to receptors that allow cells to take up glucose. Stores it in fat or glycogen. Decrease in blood glucose secretes glucagon, breaks down glycogen and glucose is released to blood.
Hunger
The physiological need to find and eat food.
Satiety
A state where you are no longer hungry. Controlled by the hypothalamus which is sensitive to glucose and insulin.
Leptin
Hormone produced by fat cells. Information about body's fat reserves. The higher the fat content, the more adipose cells, the more leptin so it tells the hypothalamus you don't need it. Decreases hunger.
Ghrelin
a hunger-arousing hormone secreted by an empty stomach
Diffusion
the process by which molecules move from an area of higher concentration to an area of lower concentration
Osmosis
The movement of water across cell plasma membranes. It depends on the differences of solute concentration of the two sides and the permeability of the membrane.
Excretory organs
Control the osmolarity of tissue fluids. Secretes some solutes and conserves others. Filtration secretion and reabsorption.
Urine
is the output of excretory system.
Osmoconformers
Equilibrate the extracellular fluid osmolarity with that of their environment. Marine invertebrates.
Osmoregulators
Maintains extracellular fluid osmolarity much lower than seawater. Marine vertebrates.
Ionic conformers
Allow the ionic composition/osmolarity to match that of their environment.
Ionic regulators
Employ active transport mechanisms to excrete some ions and maintain other ions in their extracellular fluid at optimal concentrations different than the environment
Terrestrial organisms
Must conserve water, obtain salts from food.
Protonephridia
Flatworms that are free living in freshwater. They have an extensive network of tubules. And Protonephridium.
Photonephridium
A flame cell and a tubule together, the beating of the cilia causes a negative pressure in the tubule and movements of the animal create a positive pressure in the extracellular fluid. The pressure difference causes extracellular fluid to be filtered through tiny spaces between the cells.
Metanephridia
Annelids, closed circulatory system so blood is pumped under pressure.
Malpighian tubules
Insects excrete uric acids. Tubules are attached to the gut. Active transport takes uric acid, and potassium and sodium ions. Fluid is moved towards the hindgut. Uric acid precipitates. Water follows ions out of the hindgut.
Kidney
Main excretory organ
Nephron
Functional unit of the kidney
Marine bony fishes
Must conserve water. Osmoregulate their extracellular fluids. Maintain fluids at 1/3 to 1/2 the osmolarity of seawater and take in huge amounts of salt with food.
Cartilaginous fishes
Osmoconformers but not ionic conformers. Convert nitrogenous wastes to urea and trimethylamine oxide.
Amphibians
Excrete large amounts of dilute water and conserve salts.
Reptiles
Many adaptations to dry environment. Excrete nitrogenous wastes as uric acid semisolids.
Birds and mammals
Can produce urine that is more concentrated than their tissue fluids.
The glomerulus
Filters the blood, is a ball of capillaries. Tubule fluid lacks cells and large molecules.
Bowman's capsule
Encloses the glomerulus. Podocytes come in contact with the glomerulus and they facilitate the uptake of the filtrate.
Renal tubules
Change filtrate into urine. Initial filtrate is similar to blood plasma. Controls urine composition.
Peritubular capillaries
Bring things to and carry substances away from the renal tubules.
Mammalian excretory system
Two kidneys, drained by to ureters, which go into the urinary bladder and out through the urethra.
Human kidney
As the filtrate moves from bowman's capsule it goes to the proximal convoluted tubule (still in cortex) then goes into the renal tubules and the loop of henle (medulla) responsible for the concentration of the urine. Blood vessels surround the renal tubules, Moves through the distal convoluted tubule and then into the collecting duct. And its now urine.
Effectiveness of loop of henle
Kidneys receive ~1500 liters of blood a day. ~180 is filtered into the glomeruli and there is only a ~2-3 liters of urine output daily.
Controlling acid base balance
pH effects the function and structure of proteins.
Buffer
a substance that can either absorb or release hydrogen ions. The major buffers in the blood are bicarbonate ions.
Glomerular Filtration rate
GFR Is directly dependant on blood pressure and blood volume. If blood pressure drops, you filter less blood in glomerulus. So GFR drops. Increases the diameter of the afferent arterioles. (What brings blood in) So that it fills up very quickly, more blood goes into glomerulus which raises GFR. Has an autoregulatory system.
Auto regulatory mechanisms of GFR
Dilation of afferent renal arteriole. Renin andgiotensin system, renin is released and converts a blood protein to angiotensin, angiotensin which has the end result of getting GFR getting back to normal.
Angiotensin Effects
Constriction of efferent renal arterioles. Constriction of peripheral blood vessels. Stimulates the release of aldosterone. Which stimulates sodium re absorption (to increase osmolarity of blood). Acts on the brain to stimulate thirst to increase blood volume and blood pressure.
ADH
Anti diuretic hormone. Released by the pituitary gland, gets GFR back to normal. Rise in blood osmolarity stimulates ADH release. Increases the permeability of collecting ducts to water. So adds back to blood volume. Decrease in blood osmolarity inhibits more ADH. Increases the amount of water that's reabsorbed. Rise in blood pressure can have an affect on ADH more. If there is a drop in GFR we could potentially retain urea.
ANP
Atrial Natriuretic Peptide. Released by atrial muscle fibers. Increases blood pressure. Reduces the reabsorbtion of sodium. Linked to heart failure because blood can pool in atria and cause stretching which causes a release in ANP.
Ecology
The scientific study of interactions between organisms and their physical environments. Ecological understanding helps grow food sustainably, manage pests and disease and deal with natural disasters.
Biotic
Living components of ecology
Abiotic
Non living components of ecology
Environmentalism
The use of the ecology
Weather
The short-term state of atmospheric conditions at a particular place and time.
Climate
The average atmospheric conditions over a long time. Organisms responses to climate tend to be adaptations that affect physiology, morphology and behavior and adaptations drive speciation over evolutionary time.
Global Climates
Solar powered, vary due to the amount of solar energy received. Depends on the angle of the suns rays, the bigger the angle the more atmosphere energy has to go through thus the more energy absorbed.
Global winds
Global air circulation patterns drive ocean circulation patterns or currents.
Metabolic specializations
Adaptations to climatic conditions. Estivation, hibernation, diapause. Reduced metabolic activity and enhanced physiological resistance to the adverse conditions.
Estivation
Hibernation used in dry environments; frogs
Diapause
Invertebrate form of hibernation; insects.
Hibernation
cessation from or slowing of activity during the winter; mammals.
Antifreezes
To deal with low temperature organisms produce antifreezes. The wood frog can survive -6C for over a month with 65% of its body frozen. The frog avoids damage to its cells by allowing fluids to freeze in extracellular places.
Pigmentation
Pigmentation influences heat loss and gain. Ex: Hornworm moth larvae are black if they hatch at temperatures below 20C but they are green if the temperature is higher.
Microclimate
A subset of climatic conditions in a small specific area that generally differs from those in the environment at large. Ex: Desert lizards have underground burrows.
Migration
Ones response to environmental changes
Biome
An environment that is defined by its climactic and geographic attributes and characterized by ecologically similar organisms. Distribution depends on climactic conditions. Boundaries between are somewhat arbitrary.
Tundra
Arctic and at high elevations. Low growing perennial plants and has permafrost. Summer is cool and short, winter is long and cold.
Boreal
Below arctic tundra. Winters are long at cold. Summers are short and warm. Evergreen trees. Moose, hares, rodents, birds and insects.
Temperate Evergreen forest
Coasts of continents, at middle to high latitudes. Winters are mild and wet, summers are cool and dry. Evergreen trees. Moose, hares, rodents, birds and insects.
Temperate Deciduous Forest
North america, eastern asia, europe. Temperatures fluctuate dramatically. Deciduous trees lose leaves in the winter. Rich animal life, migrant birds, amphibians insects.
Temperate Grasslands
Relatively dry. Hot summers and cold winters. Lots of mammals, few birds. Lots of plants. Good to grow in.
Hot desert
Found in two belts around the 30* latitudes. Driest regions. Lots of rodants, bees, reptiles and butterflies. Plants that have extensive root systems. Hot in winter and summer. Lack of water conservation.
Cold desert
High latitudes. Dry. Low growing shrubs. Birds ants rodants. Winter is cold and dry summer is warm and dry.
Chaparral
Hot dry summers, wet cool winters. Rodents reptiles and insects. Low growing shrubs. Western sides of continents at mid latitudes.
Thorn forests and tropical savannas
below the hot deserts of Africa, South America and Australia. No rain in winter but heavy in summer. Winter is dry and mild, summer is wet but not much warmer. Shrubs and small trees. Rich mammals, birds reptiles and insects.
Tropical Deciduous forests
deciduous trees, lots of trees, mammals, birds, reptiles, and amphibians and insects. winter is dry and hot summer is hot and wet. soils are good for agriculture
Tropical Evergreen forest
Trees and vines, lots of animals, birds, amphibians and arthropods. Very warm and rainy all year. Being destroyed.
Rain shadow
When winds bump into mountain ranges, the air rises up, cools and releases moisture. That side is particularly lush. The now dry air descends down the leeward side which results in dry areas on that side.
Evolutionary history
Where and when groups originated. An important determinant of the distribution of species. It is influenced by geological species.
Biogeography
The study of patterns of distributions of populations, species, and communities.
Acceptance of continental drift. Development of phylogenetic taxonomy.
Biogeographic regions
Characteristic species assemblages. Boundaries occur where species composition changes dramatically over short distances. These regions have barriers to dispersal between them, such as mountains or oceans.
Endemic
Species found only in a certain region.
Phylogenetic
a biological classification of organisms according to the evolutionary history
Area phylogenies
taxa names replaced with places where the taxa live or lived
Biotic interchange
Dispersal of species from different biotas into new regions when land masse fuse.
Vicariant events
Appearance of a physical barrier that splits into the range of a species.
Dispersal
If organisms cross an existing barrier and establish a population. Results in discontinuous ranges.
Human activity
Another force capable of generating unusual distribution patterns.
Aquatic Environments
Oceans are divided into several life zones. Ranges of marine organisms are restricted by water temperature, salinity, and food supply.
Photic zone
Enough light to support photosynthesis.
Coastal zone
Extends from the shoreline to the edge of the continental shelf.
Littoral zone
The coastal zone that is affected by wave action.
Intertidal zone
Lies between high and low tide levels.
Pelagic zone
The open ocean. Free swimming species.
Benthic zone
Ocean bottom; organisms that have adapted to life on the sea floor.
Aphotic zone
Depths reached by less than 1% of incoming sunlight
Abyssal plain
The deep ocean floor.
Freshwater environments
Streams, rivers, lakes and ponds. Cover less than 3% of Earth's surface but are home to 10% of all aquatic species.
Estuaries
Form where rivers meet the ocean, and salt water mixes with fresh water. Home to many unique species with high diversity. Have a role in purifying groundwater.