After returning from his 5 year voyage, Darwin determined that adaptions of organisms develop over time. He proposed natural selection asa mechanism for evolutionary change. List Darwin's five mechanisms of natural selection.
1. The members of a population have heritable variation.
2. In a population, many more individuals are produced each generation than the envirnoment can support.
3. Some individuals have adaptive characteristics that enable them to survive and reproduce better than other individuals.
4. An increasing proportion of individuals in suceeding generations have the adaptive characteristics.
5. The result of natural selection is a populatio adapted to its local environment.
the process of adapting to something (such as environmental conditions)
Structures found in different species that are anatomically similar because they have been inherited from a common ancestor.
Example: Page 296 Forelimbs
Remains of an anatomical structure that are functional in an ancestor but are not currently functional.
Examples: Humans have a tail bones, Snakes remnants of apewic girdle and legs.
Evidence that supports evolution includes fossil evidence, biogeographical evidence, anatomical evidence and biochemical evidence. Discuss each of these ideas and how they support the theory of evolution.
Fossil evidence - Fossils must be atleast 10,000 years old. Fossils show change over time. The only flaw is that organisms without bones, exoskeletons, etc are not part of record.
Biogeographical evidence - Geographic distribution of plants, and animals throughout the world. (Pangea)
Anatomical Evidence - There are anatomical similarities that serve the same function but are constructed differently.
Biochemical Evidence - Almost all organisms use DNA and the same triplet code and 20 amino acids
- they also use ATp and nearly identical enzymes.
-Many genes are similar.
Evolution will NOT occur if the five conditions of Hardy Weinberg principle are met. List the 5 conditions.
1) random : individuals are free to pair with any other member of a population. Individuals will pair by chance and not according to their genotypes or phenotypes.
2) Large Population: the population must be very large so that genetic drift is insignificant. Genetic drift: in small populations, an allele can become more or less common by chance.
3) There can be no movement, or gene flow, into or out of a population.
4) There can be no mutations in alleles.
5) There can be no natural selection where on genotype is favored over another.
*UNDER THESE CONDITIONS, NO EVOLUTION IS TAKING PLACE.
-Defined as the movement of alleles.
-migration: gene flow decreases genetic diversity because gene pools are similar.
-Can take place between large and samll populations.
- Big impact on small populations.
-Defined as the random changes in allele frequencies due to chance.
-Bottleneck effect: the majority of genotypes are prevented from participating in the production of the next generation due to a natural disaster or human interference. Alleles can be lost from a population.
-Founder effect: rare alelles occur at ahigher frequency in a population that is isolated from the general population.
"Survival of the fittest"
Variation - the members of a population differ from one another.
Inheritance - different traits can be inherited.
Differential Adaptiveness - difference affect how well an individual is adapted to the environment.
Differential Reproduction - individuals who are better adapted to the environment are more likely to reproduce.
occurs when an extreme phenotype is favored
-distribution curve in one direction.
Example: Body size of a horse overtime.
- Intermediete phenotype is favored
- environment remains constant.
Example: in human population, intermediete birthweight (not to fat, not to skinny) = better survival.
Example 2: Birds are better off laying 5-6 eggs for survival.
- 2 or more extreme phenotypes are favored over intermediate phenotype.
Example: Sanils have a wide range of habitat.
a group of interbreeding organisms that can breed and produce offspring.
- splitting of 1 species into 2 or more new species.
- origin of a new specie is due to changes in the gene pool and alllele frequencies over time
Reproductive Isolating mechanisms can result in the development of new species. Define Habitat isolation.
Species in the same location occupy different habitat
-Animals in rainforest occupy particular levels of forest canopy caused isolation from similar species.
Reproductive Isolating mechanisms can result in the development of new species. Define temporal isolation.
- Species reproduce at different times
- 5 similar species of frogs in Ithica, New York remain seperate because they have different mating times.
Reproductive Isolating mechanisms can result in the development of new species. Define Behavioral Isolation.
- Species are capable of breeding but have differences in courtship patterns
-fireflies find other fireflies of the same type by the specific light pattern
Adaptive radiation is considered a type of allopatric speciation. The result of adaptiv radiation is the evolution of several species from a common ancestor in new geographic regions. The new species have adapted to different environments.
Darwin's finches are examples.
What is relative dating of fossils?
Index fossil - organisms lived a short period of time, they are umbundant and distintive.
Relative Dating - uses index fossils to give a broad time line.
What is absolute dating of fossils?
Aboslute dating - calculate age of age based on isoptes
Half-life - Amount of time required for half the radioactive elements to decay a stable electron
The study of Identifying, naming and classifying orgnaisms
Define: Binomial nomenclature. What are the rules for naming a genus and species?
Each species recieves a 2 part name. The first name is the genus, and may contain many species, The secondname is specific to the species.
Define: Phylogenetic tree, analogous structures.
Phylogeny: is an evolutionary history, usually a tree.
Analogous Structures: The wings of an insect and the wings of a bat are analogous. This means that they have the same function in different groups but do not have a common ancestry.
Lit and briefly describe the three domains.
Consists of cell: No.
Respond to stimuli: No.
Multiply: Yes (always in living cell)
Evolve: Yes. (think of swine flu).
What organelles are found in bacteria?
-The outer cell wall contains: Peptidoglycan and strengthens the cell wall.
-Cell wall prevents collapse due to osmosis.
- A capsule slime layer outside the wall is composed of glycolaxs which protects bacteria.
-Durnig adverse conditions, some bacteria form endospores.
- a thick wall enclose the DNA and some cytoplasm.
The act of Prokaryotes reproducing asexually.
Occurs between bacteria when the donor cell passes DNA to the recipient cell by way of sex pilus which temporarily joins two cells.
Occurs when a bacterium pick up (from the surroundings) free pieces of DNA secreted by live prokaryotes or released by dead prokaryotes.
When faced with unfavorable environmental conditions, some bacteria produce this.
Describe Protists and their ecological importance.
-several cause disease in humans
-give off oxygen in aquatics (function as producers in salt and fresh water)
-They are a part of plankton.
-enter symbiotic relationships ranging from parasitism and mutualism.
Simple squamous epithelial tissue:
-lining of lungs, blood vessels
Simple Columnar epithelial tissue:
-lining of small intestine, oviducts
Stratified Squamous tissue:
-lining of nose, mouth esophagus, anal canal, vagina
Loose fibrous connective tissue:
-has spaces between components.
-occurs beneath skin and most epithelial layers.
-functions in support and bind organs.
Dense Fibrous connective tissue
-has collagenous fibers, closely packed
-in dermis of skin, tendons, ligaments.
-functions in support.
-Cells are filled with fat.
-Occur beneath skin, around heart and other organs
-functions in insulation, stores fat.
Blood is considered a __ __ Tissue
Red blood Cell
Red Blood Cells (RBC) are also called arethocytes. They are biconcave disks that lack a nucleus when mature. They contain hemoglobin to transport oxygen from tissue. They also carry Carbon Dioxide from tissue. Red Blood Cells live 120 days. They are produced in the red bone marrow. This is found in the ends of longbones , the ribs, the vertebral colum, and bones in the skull in adults.
White Blood Cell
Each antibody combines a specific antigen. This will then be marked for destruction. They will be engulfed by white bloods cells.
1. Guard against infection.
-fights parasites and attack bacteria
2. When we are exposed to an infection, the number of WBC is increased to fight the foriegn substance.
Platelets cause blood to clot.
Plasma makes up 55% of blood volume. It is 90% water and also contains proteins, salts, gases, nutrients, wastes, hormones, vitamins, etc. Salt and proteins buffer the blood and keep it at a pH level of 7.4 (More basic).
The remainder of blood is composed of formed elements.
WBC - 45%. Whiteblood cell and plalets - less than 1%.
Body's maintenance of internal conditions.
activity is suppressed (slowed down) or inhibited (stopped). (secretes insultin when glucose levels are too high).
Activity is increased.
How many chambers does the heart contain? What structure prevents oxygen poor and rich from mix?
THE SA NODE: intiates heart beats every 85 seconds.
The sinoatrial Nodes sends out a stimulus which causes the atria (upper chambers that receive blood).
THE AV NODE: keep heart beat regular (called the peace maker). Sends signal to ventricles to contract through the Puninje
When the SA stimulus reaches the AV node, it signals the ventricles to contract. Impulses pass down the two branches of the AV bundle to the purkinje fibers and cause them to contract.
How do red blood cells carry oxygen?
Hemoglbin contains four globin chains, which contain iron. Iron combines with oxygen and in this way, oxygen is carried in the blood.
Give an overview of blood clotting when an injury occurs.
When a blood vessel in the body is damages, platelets clump at the site of the puncture and partially seal the leak. Platelets and injured tissues release a clotting factor (thrombin),....
What are the functions of the lymphatic system that contribute to homeostasis?
1. Lymphatic capillaries absorb excess tissue and return it to the blood stream.
2. In the small intestines, capillaries (lacteals) absorb fats (lipoproteins) and transport them back to the bloodstream.
3. responsible for lymphcites
4. helps defend against pathogens.
Describe the 4 nonspecific defenses: barriers to entry, imflammatory response, phagocytes, natural killer cell and protective proteins.
skin - prevents pathogens from entering or dispersing into the body.
Mucous membranes line the respiratory, digestive and urinary tracts and prevent them from residing. (oils, stomach acid, etc)
2. Inflammatory response
forces the injured region to rest and aids in healing.. histamine is released.
3. Phagoctytes and natural killer cells
phagocytes: engulf pathogens.
natural killer cells: kill virus infected cells and cancer cells by cell to cell contact.
Foreign substances (living of nonliving) that stimulate the immune system to react and produce antibodies
Disease causing agents - bacteria, viruses, protists, fungi, etc.
Proteins produced by the immune system in response to an antigen.
B cells: (2 other cells)
B cells: Produce plasma cells and memory B cells.
-Plama cells: produce specific antibodies
-memory cells: ready to produce antibodies in the future.
T cells: Regulate immune response; produce cytoxic T cells, helper T cells, and memory T cells.
-cytotoxic: kill virus infect and tumor cells.
-helper T cells: regulate immunity
Memory T cells: Ready to react to antigens in the future
Phagocytize pathogensl inflammatory response and specific immunity.
Why can Opportunistic infections prove fatal to someoe with AIDS?
Initially when exposed to HIV, and individual can produce enought T cells to keep the HIV count low. Eventually the helper T cell count well before normal. At this point, opportunistic Infections occur.
What's the difference between active immunity and passive immunity?
1. Through infection.
2. Vaccine or immunization.
3. First exposure:
- few antibodies are present.
- slow rise in antibodies.
- eventually antibodies will bind antigen.
4. During a second exposure:
-response: much quicker and more intense.
- Long lasting immunity.
Passive Immunity: short lived, does not last.
Follow the path of food through the mouth, esophagus, stomach, small intestine, large intestine, and anus.
Mouth - Chewing of food; digestion of strach.
Esophagus - Movement of food by peristalsis
Stomach - Storage of food; acidity kills some bacteria; digestion of proteins.
Small intestines - digestion of all food; d of nutrients.
Large intestines - absorption of water storage of non digestible remains.
What are the functions of the liver?
1. Detoxifies blood by removing and metabolizing poisonous substances.
2. stores glucose as glycogen after a meal. and break down glycogen to glucose to maintain the glucose levels of blood between eating periods.
The kidneys filter ___ and ___. They also produce __. This takes place in funtional unites called ___.
The Kidneys filter blood and regulate fluids. They also produce urine. THis takes place in functional unites called nephrons.
Describe the gas exchange at the alveoli in the lungs.
Respirations is the exchange of oxygen and carbon dioxide between the air, blood, and tissues. It goes from the pharynxs to the larnyx, tarchea, bronchi, lungs. Gas exchange takes place with diffusion and occurs between air in the alveoli and blood within a capillary network that surround the alveoli.
List the three types of neurons and describe the functions.
Motor Neurons: take nerve impulses from the CNS to muscles or glands.
Sensory Neurons: take nerve impulses from sensory recptors to the CNS.
Interneurons: Occur in the CNS. Convey nerve impulses between various parts of the CNS.
Branching regions that recieve and transmit signals towards the cell body.
Conducts impulses from the cell body to synapse.
contains the the necleus and organelles (found in motor neurons.. idk if there is others)
Axons can be covered by a myelin sheath that insulate the nerve fibers.
Nodes of Ranvier
Gaps in myelin sheath that speed up nerve signals
2. Spinal Cord
The CNS is wrapped with 3 protective membranes calles meniges. Spaces between the memiges are filled with cerebrospinal fluid.
Peripheral Nervous system
All other regions outside the brain and spinal cord.
Somatic Nervous System:
-controls voluntary movement.
-Nerves take sensory information to brain.
-Info is processed and sent back through motor neurons.
-reflex arc: processed in spinal cord
-Controls invounary movement.
-Regulates smooth musce, cardiac muscle and glands.
Broken up into two parts:
-important during emergency
- "fight" or "flight" response.
-Heart rate increases.
-glucose and oxygen increases in muscle.
-promotes digestion of food.
-Slows heartbeat, etc.
Desribe the axon membrane during an action potential as it moves through the axon membrane.
-no nerve impulse pass through neuron.
Inside axon: -
Outside of axon: +
The difference of charges is due to:
1. Sodium-potassium pump which moves 3 sodium ions (NA +) out of the axons fro every 2 potassium ions (k+) it moves into axon.
2. Two negatively charged proteins, amino aicd, etc are found inside the axon membrane. The result is more + ions outside membrane.
During an Action potential..
A nerve impulse move through the axons. The charges in and out reverse. What takes place as the nerve impulse moves through the axon membrane. The Sodium gates open, and the Na + molecules move across the membrane into the nerve cell.
-Charge inside axon membrane is now +
- Charge outside is now negative. -.
Transmission of a Nerve impulse across a synapse.
Axons branch into axon terminals that lie close to the cell body or the dendrite of another neuron. This region is called a synapse. As the nerve impulse moved to the axon terminal, calcium gates open. Calcium cause synaptic vesicles to bind with the membrane of axon terminal. Synaptic vesicles release neurotransmitters into a synaptic cleft. Once the neurotransmitter is bound to a receptor site, the nerve impulse will be initiated in the post synaptic neuron. The signal can cause excitation or inhibition to take place. There are about 100 different types of neurotransmitters
-largest portion of the brain
-Consist of a thin, highly convoluted (highly complex and difficult to follow) (ridged) outer layer. These deep convolutions are called the gyri. The gyri increase surface area.
- contains billions of neurons.
-recieves sensory input and sends out motor responses.
- coordinates the activities of other parts of the brain.
- controls volunary movement (moving arm..)
- contols higher thought processes (conscience thought)
- 2 hemisphere which control opp sides of the body.The right and left hemispheres are connected by the carpus collosum.
-Located at the base of the brain. THe cerebellum recieves sensory input from the eyes, ears, joinst, and muscles about the body's orientations. The cerebellum assists in motor skills (playing piano; hitting a ball).
-regulates hunger, sleep, thirst, temperature, water balance.
-Controls the pituitary gland and links the nervous and endocrine system.
-regulates breathing and heartbeat
- reflex center for vomtting, coughing, sneezing, swallowing.
The limbic system incorporates several regions of the brain. Its organs include the hippocampus and amygdale.
It is important in:
-associates memories (smell of smoke means fire)
Allows you to respond more quickly to stimuli. When sensory receptors respond:
-the signal remains the same
- does not travel
-touch something sharp (move your hand away).
Any environment has a mzximum number of individuals of a give species that it can support.
-fast to mature
-many offspring (most likely to survive a population crash)
-little or no care for offspring
-many offspring die before reproducing
-early reproductive age
Examples: Annual plants (dandelions), bacteria, fungi, insects and rodents
-slow to mature
-few and large offspring
-care for young
-most young survive to reproductive age
-adapted to a stable environment
Examples: Large mamals, long-lived plants, oaks and pines, birds of prety, hawks, and eagles.
List the species interactions and outcomes
Competition - abundance of both species decrease.
Predation - abundance of predator increases.
Convert nitrogen into ammonia.
When soil bacteria converts nitrates into nitrogen gas nitrogen into atmosphere.
Competetive exclusion principle
States that nno 2 spcies can occupy the same niche at the same habitat at the same time.
Both species benefit.
one species benefit and the other is not helped nor harmed.
Sucession where no soil exsist.
When a disturbance changes an exsisting community without removing the soil.