WEST-E Biology Certification Study Guide
Terms in this set (295)
What does energy flow mean?
actual caloric flow through a system from trophic level to trophic level.
What percent of energy is passed on to each trophic level?
Define and give examples of biotic factors
o living factors, such as other organisms that affect a community or population.
♣ Organisms, predation, disease, competition, parasitism, consumption, and symbiosis (interaction of two organisms living in close proximity).
Define and give examples of abiotic factors
o non-living factors that affect a community or population, such as facets of the environment.
♣ Non-living chemical and physical parts of the environment.
• Water, light, radiation, temperature, humidity, atmosphere, and soil.
What are the three levels for biomes?
High (least sunlight), middle, and lowest (warmest) latitudes.
Six major types of biomes
freshwater, marine, desert, forest, grassland, tundra.
all of the animal life of any particular region or time
all the plant life of any particular region or time.
different types of rainforest
♣ Two types: tropical and temperate, both having high amounts of rainfall.
• Tropical have the highest biodiversity in the world.
• Temperate have high rainfall, but cooler temperatures.
Explain the tundra
♣ Found in artic circle in northern hemisphere and on the tops of very high mountains.
♣ Coldest and driest of all the biomes.
special feature of tundra
ground is permanently frozen
explain the taiga
♣ Made up of coniferous forests and is the largest of all land biomes.
♣ Located in the northern part of the world throughout Canada, Asia, and parts of Europe.
♣ Winters are very colds, but summers are very sunny.
♣ Temperatures rarely climb above 50.
Flora in taiga
evergreen trees with needles such as fir and spruces.
Explain the desert
♣ Extremely dry and extremely hot.
♣ Only plants and animals that can adapt to these conditions will survive.
♣ Found all over the world.
Explain the grassland
♣ Found on every continent except Antarctica.
♣ Enough rainfall to support grasses and non-woody plants (flowers and herbs), but drought and fire prevent large fires from growing.
♣ Fauna: known for the bison's habitat.
explain the marine
♣ Oceans, coral reefs, and shorelines.
♣ Many animals are specially adapted to these ecosystems and cannot live anywhere else.
Primary ecological succession
♣ initiated when a new are that has never previously supported an ecological community is colonized by plants and animals.
• This could be newly exposed rock surfaces from landslides or lava flows.
Secondary ecological succession
♣ occurs when an area that has previously had an ecological community is so disturbed or changed that the original community was destroyed and a new community moves in.
• More common than primary succession and is often a result of natural disasters and human interference.
Define biogeochemical cycles
movement of matter through a system
Explain water cycle
♣ Continuous movement of the water
♣ Heat from sun causes water to evaporate from oceans, lakes, rivers, and other bodies of water.
♣ As plants transpire, this water also undergoes evaporation
♣ Water vapor collects in the sky and forms clouds.
♣ As water vapor cools, it condenses and moves back to the ground via precipitation.
Carbon cycle and the movement of carbon
♣ Carbon moves from atmosphere to plants via photosynthesis.
♣ Moves from plants to animals via food chain.
♣ Moves from living organisms to soil when the animal dies.
♣ Moves from living organisms to atmosphere through respiration.
♣ Moves from atmosphere to the oceans and freshwater systems via absorption.
♣ Most organisms cannot use nitrogen in this form (N2) so it must be converted into some type of nitrate.
• Lightning causes nitrates to form in the air and can be carried to to the soil by rain to be used by plants.
♣ Nitrifying bacteria in the soul can also convert ammonia into nitrates.
♣ Plants absorb nitrates from the soil and animals can consume the plants and other animals for protein.
♣ Found in rocks.
♣ When it rains, phosphates can be dissolved into the water.
♣ Plants are able to use phosphates from soil (needed by plants for growth and development).
♣ Plants and algae can absorb phosphate ions from the water and convert them into many organic compounds.
♣ Animals get phosphorus from eating plants or other animals and drinking water.
Leibig's Law of the Minimum
growth is controlled not by the total amount of resources available but by the scarcest resource.
Define ecological niche
o Niche describes an organism's functional role in the community.
o Can be complex because it should include the impacts that the organism has on the biotic and abiotic surroundings.
o Describes how an organism or population responds to the distribution of resources and competitors.
o Focuses on spatial patterns of ecological communities.
explain the logistic population growth model
♣ With logistic models: rate of population growth decreases as population size increases.
• logistic growth levels off once the population have reached carrying capacity.
• This limits the number of individuals that can occupy a habitat.
explain the exponential population growth model
♣ Rate of change is proportional to the increasing size in an exponential progression.
♣ Does not take into account limiting factors or carrying capacity.
♣ Special nutritional relationship among different species.
♣ Two organism share a close physical relationship that can be helpful, harmful, or neutral for each organism.
Examples of symbiosis
• One organism benefits (parasite) while the other is harmed because its not getting anything in return (host).
o Ex. Tick and dog.
• One benefits and the other is not affected.
o Small fish rides on the belly of a shark and is protected.
• Both organisms benefit.
o Ex. Tick birds remove ticks from rhino. Birds get food and rhino gets ticks taken off of them.
♣ One is predator and other is prey.
♣ Predator benefits from the relationship but the prey is harmed.
Why can predation be beneficial?
♣ Predation keeps the prey species under control and prevents them from overshooting the carrying capacity, which often leads to starvation.
♣ Helps remove the weak and slower members of the prey species.
♣ Relationship between two organisms where they compete for the same vital resource that has a limited supply.
♣ Typically, both organism are harmed, but usually one is more harmed than the other.
♣ Territoriality: interspecific competition for space.
♣ Competition: avenue for natural selection.
Difference between inter and intraspecific competition
♣ Interspecific competition:
• Between different species.
♣ Intraspecific Competition:
• Between same species.
♣ Self-sacrificing behavior in which an individual animal may serve or protect another animal.
types and sources of environmental pollution.
o Air pollution:
♣ Contamination of air by smoke and harmful gases.
o Land pollution:
♣ Caused by misuse of resources and improper disposal of waste (ex. Deforestation).
Introduced species and its effect on biodiversity
♣ Invasive or nonnative species.
♣ Decrease biodiversity by by using limited resources and preying on other members of the community.
♣ Free from predators and can reproduce exponentially.
Habitat fragmentation by humans
♣ Humans have cleared much land for agriculture and urban developments.
♣ Habitats are fragmented into smaller areas, which only allow for small populations that are under threat by predators, diseases, weather, and limited resources.
causes and biological consequences of global warming
o Greenhouse gas emission increases temperature over land, ocean, in the ocean, and even in the troposphere.
o Increased temperature effects:
♣ More extreme weather events.
♣ Shift tourism and improve agriculture.
♣ Decrease glaciers, sea ice and sheets which will lead to rising sea levels.
• Rising sea levels lead to habitat change or loss.
♣ Earlier snowmelt and runoff may overwhelm water management systems.
Clean Air Act
♣ New industrial sites are designed and built with pollution-control technology fully integrated into the facility.
♣ New coal-fired power plants are fitted with pollution-control devices that greatly reduce and nearly eliminate sulfur dioxide and nitrogen oxide emissions.
Advantages and disadvantages of sexual reproduction
♣ Advantages: genetic variation which assists with survival.
♣ Disadvantages: requires two parents.
Zygote undergoes cell division to form an ____?
• Some embryos develop into eggs or mammals who are viviparous have a uterus in which the embryo develops.
Advantages and disadvantages of asexual reproduction
♣ Disadvantage: lack of genetic variation.
♣ Advantageous in a stable environment. But if the environment changes, the organisms may lack genetic variability to survive or selectively adapt.
List and explain the 4 stages of embryonic development
♣ 1. Cleavage: occurs immediately after fertilization when large-celled zygotes begins to divide.
♣ 2. Patterning: gastrulation occurs.
• Cells are organized into three main germ layers: ectoderm, mesoderm, and endoderm.
♣ 3. Differentiation: Cells in these layers differentiate into special tissues and organs (organogenesis).
♣ 4. Growth: further tissue specialization before hatching or birth.
Special feature of embryonic stem cells
o Embryonic stem cells can become all cell types because they are pluripotent.
Why are adult stem cells thought to be limiting?
limited to differentiating into different cell types of their tissue or origin due to not being able to express certain portions of the genome.
Explain plant life cycle
♣ Alternates between haploid and diploid generations.
• Sexual phase: gametophyte
o Sperm fertilizes the egg to form zygote.
Asexual phase: sporophyte
For plant life cycle: embryonic development is only seen in which generation?
For plant life cycle: embryos are only seen in which generation?
Gametes develop in the multicellular haploid _________.
Fertilization gives rise to a multicellular diploid ________
Methods of reproduction for plants
♣ Many plants reproduce by seeds produced in the fruits of the plants.
♣ Some plants reproduce by seeds on cones.
♣ Ferns reproduce by spores.
♣ Some plants reproduce asexually by vegetative reproduction.
Cycle of plant life
♣ Seedling --> mature plant--> flower --> seed-->back to seedling.
Explain animal life cycle
♣ Sexual reproduction.
♣ Involves the union of sperm and egg to produce a zygote.
Fungi life cycle
♣ Almost all reproduce asexually by spores, but most fungi also have a sexual phase in the production of spores.
♣ Some fungi reproduce by budding and fragmentation.
Reproductive success and example
♣ passing of genes onto the next generation in a way that that they too can pass on those genes.
• Kin selection:
o Combines the number of offspring produced with the number an individual can produce by supporting others such as siblings.
♣ Ability to survive to reproductive age, find a mate, and produce offspring.
♣ The more offspring an organism produces during its lifetime, the greater the biological fitness.
Levels of biological organization for multicellular organisms
o Cells, tissues, organs, and then organ systems.
• Composed of various molecules including proteins, carbs, lipids, and nucleic acids.
• All cells have a nucleus, cytoplasm, and a cell membrane.
• Group of cells that work together to perform a specific function.
Four types of tissue
Muscle Tissue and the three different types and where they're form
♣ Involved with body movement,
♣ Composed of skeletal, cardiac, or smooth muscle cells.
♣ Cardiac: found in heart.
♣ Skeletal: found in muscles.
♣ Smooth: tension in blood vessels, control pupil dilation, aid in peristalsis.
Nerve tissue location
♣ Located in brain, spinal cord, and nerves.
What does epithelial tissue make up?
♣ Makes up layers of the skin and various membranes.
What does connective tissue make up?
♣ Bone tissue, cartilage, tendons, ligaments, fat, blood, and lymph.
11 major organ systems
o Integumentary, respiratory, cardiovascular, endocrine, nervous, immune, digestive, excretory, muscular, skeletal, reproductive.
Two types of plants
vascular and non vascular
Characteristics of vascular plants
♣ Has dermal, meristematic, ground, and vascular tissues.
♣ Can grow tall and are found in dry regions.
♣ Has leaf, root, and stem systems.
Examples of vascular plants
♣ Angiosperms, gymnosperms, and ferns.
What are angiosperms and how do they reproduce?
• Flowering plants
• Reproduce by producing seeds that are enclosed in an ovary, usually a fruit.
• Grass, weeds, garden flowers, vegetables, or broadleaf trees.
Monocot vs. Dicot for angiosperms in terms of seeds, petals, vascular bundles, and root systems
• Seeds of monocots have one cotyledon and dicots have two cotyledons.
• Petals on flowers of monocots: 3. Petals on flowers of dicots: 4,5.
• Vascular bundles in monocots are distributed throughout the stem.
• Vascular bundles in dicots are arranged in rings.
• Monocots have fibrous roots and dicots have taproot systems.
What are gymnosperms and how do they reproduce?
• Nonflowering plants
• Reproduce by enclosed seeds on scales, leaves, or cones.
• Conifers such as pines, spruces, cedars, and redwoods.
Characteristics and examples of vascular plants
♣ Do not have vascular tissue xylem and phloem.
♣ Stay close to the ground and found in moist environment.
♣ Mosses and liverworts.
Different plant tissues
Dermal tissue components and function
• Consists of dermis and epidermis.
• Epidermis protects the plant by secreting the cuticle, a waxy substance that prevents water loss.
o Has stomata: tiny pores that are regulated by guard cells.
o Replaced by periderm in older plants (bark).
♣ Protects plant and provides insulation.
Vascular tissue components and function
• All vascular plants contain tracheids, but only angiosperms contain vessel elements.
• Xylem and phloem.
o Xylem: provides support and conducts water and dissolved materials from the roots and upward throughout the plant.
o Phloem: conducts nutrient movement throughout the plant.
o Bound together in vascular bundles.
Ground tissue components and function
• Three major types:
o Parenchyma: provides photosynthesis, food storage, and tissue repair.
o Collenchyma: provides support to roots, stems, and petioles.
o Schlerenchyma: contains cellulose and lignin.
♣ Support and protection.
Meristemic tissue components and function
• Meristemic cells produce all new cells in a plant and regenerate damaged parts.
• Reproduce asexually through mitosis or cell division regulated by hormones.
• Regions of plant growth.
• Totipotent cells: they can always develop into any type of special tissue.
• Two types:
o 1. Lateral
o 2. Apical
Two major organ systems in plants
root and shoot systems.
Function and components of flowers
♣ Primary function: to produce seeds for reproduction of the plant.
♣ Receptacle holds the developing seeds.
♣ Sepals protect the bud.
♣ Petals help attract pollinators.
♣ Stamen consists of anther and filaments
♣ Anther produces pollen which produces sperm cells.
♣ Ovary consists of ovules which house the egg cells.
Function and components of stem
♣ Divided into nodes and internodes.
♣ Buds are located at the nodes and may develop into leaves, roots, flowers, cones, and more stems.
♣ Consists of dermal tissue, ground tissue, and vascular tissue.
♣ Dicot stems have vascular bundles
♣ Main functions:
•Provide support to leaves, flowers, and fruits.
•Transport materials in the xylem and phloem.
•Have meristems which provide all the new cells of the plant.
Function and components of roots
♣ Manufactures food through photosynthesis.
♣ Veins transport food and water and make up the skeleton of the leaf.
♣ Epidermis is covered by a protective cuticle.
♣ Lower epidermis contains many stomata and pores which allows air to enter and leave the leaf.
♣ Stomata regulate transpiration.
Function and components of roots
two root systems
♣ Anchors the plant, absorbs water and minerals, and store foods.
♣ Taproot and fibrous root systems.
• Primary root with many smaller and secondary roots.
♣ Fibrous: lack primary roots, but has many secondary roots.
Three regions of the root
♣ The root has three main regions:
• Area of maturation
• Area of elongation
• Area of cell division
♣ Root hairs absorb water and minerals via osmosis.
Center of the root which contains xylem and phloem
Homologous structures and example
• similar in different species because of similar ancestry.
• Ex. Forelimb structure shared by cats and whales.
Analogous structures and example
• similar in different organisms because they evolved in a similar environment rather than inherited from a similar ancestor.
• Ex. Torpedo body shape of porpoises and sharks.
o Developed analogous structures as a result of evolution from same aquatic environment.
Difference between heterotrophs and autotrophs
o Autotrophs and plants: produce energy through photosynthesis and chemosynthesis.
♣ Capable of self-nourishment by using inorganic materials.
o Heterotrophs: obtain their energy from consuming autotrophs and other heterotrophs.
♣ Require food and use cellular respiration to release energy from chemical bonds in the molecules of that food.
proteins, nucleic acids, carbohydrates, lipids.
How does water and inorganic nutrients enter a plant?
o Water and inorganic nutrients enter through the plant's root hairs by osmosis and active transport and pass through the endodermis to the xylem.
What regulates water loss in plants?
Guard cells control stomata to regulate water loss
Energy for long term storage in animals are stored in?
How does minerals, water, and carbs move through a plant?
♣ Minerals and water move through xylem.
♣ Carbohydrates move through the phloem.
How does minerals, water, and carbs move through an animal?
♣ Digestive system:
• Allows for absorption of nutrients within the intestines.
• These nutrients are used for many different functions throughout the body.
• Fat soluble vitamins are absorbed by fat.
Function of integumentary system
protection, secretion, and communication.
Secretion in integumentary system
♣ Secretes sebum (oil) what waterproofs skins and sweat glands are associated with homeostatic relationship of thermoregulation.
• Sebum is oily mixture of lipids and proteins.
o Inhibits water loss from skin and protects against bacterial and fungal infections.
Communication in integumentary system
sensory receptors send information to brain regarding pain, touch, pressure, and temp.
Three types of tissues in muscular system
• 1. Skeletal:
o also known as striated due to their striped appearance.
• 2. Smooth:
o found in sphincters or valves that controls various openings throughout the body.
• 3. Cardiac:
o involuntary muscle that is found only in the heart.
Explain muscle contraction
• Numerous muscle fibers.
o Each fiber contains a bundle of myofibrils.
♣ Myofibrils have both thick and thin filaments.
♣ Thick: myosin
♣ Thin: actin.
• When there is an action potential reaches the muscle fibers, calcium ions are released.
• Calcium binds to to myosin and actin which assists in the binding of the myosin heads of the thick filaments.
• ATP released to provide energy necessary for the contraction.
What are the thin and thick filaments in muscle contraction
Thermal regulation in muscle contraction
• When body temp. drops too low, the hypothalamus signals the body's warming mechanisms to initiate.
• Skeletal muscles are triggered and shivering generates heat.
Different types of bones in skeletal system
• compact (cortical) - strong, dense, and rigid.
• Spongy (Trabecular) - network of girders with open spaces filled with red bone marrow.
What does red marrow do?
helps manufacture red and white blood cells.
• Provides for a reservoir for Calcium and phosphorus for the blood.
Functions of skeletal system
• Structural support
• Provides movement
• RBC and WBC production
• Reservoir for calcium and phosphorus.
Function of skeletal system in homeostasis
(think osteoclasts and osteoblasts)
• Bone remodeling.
o Osteoclasts: continually destroy mature bone tissue (bone resorption)
o Osteoblasts: construct new bone tissues including collagen fibers (deposition).
Role of digestive system in homeostasis
• Maintains pH balance and balance of helpful bacteria.
o Stomach has the most acidic pH to destroy harmful pathogens.
Peristalsis in digestive system
o Involuntary muscle contractions which moves food to esophagus and into stomach through lower esophageal sphincter.
3 layers of small intestines and their functions
o Duodenum: continues breaking down goof with help from liver, pancreas, and gallbladder.
o Jejunum and ileum: has villi for absorption.
Function of large intestines
Process of digestive system
o Mouth, throat, esophagus, stomach, small intestine, large intestine, rectum, and anus.
Role in homeostasis of excretory system
• Regulation of blood volume and blood pressure.
• If blood volume drops too low, ADH is released, increased the resorption of water.
• As blood volume increases, blood pressure increases.
signals kidneys to conserve water and sodium which increases blood volume and blood pressure.
Role of kidneys in excretory system
• Filter the blood, reabsorb needed materials, and secrete wasted and excess water in the urine.
Two phases of circulatory system
♣ First diastole phase:
♣ Second diastole phase:
Type of circulations
o Flow of blood to the entire body except the other two types of circulation.
• flow of blood to the heart tissue.
o Blood enters coronary arteries, which branch off the aorta, supplying major arteries with oxygenated blood.
o Flow of blood between the heart and lungs
♣ Flow of blood from the digestive system to the liver and then to the heart
♣ Flow of blood between the heart and kidneys.
Role on homeostasis of circulatory system
• Regulates level of oxygen, nutrients, and wastes in blood.
• Provides blood volume for the needed pressure for the kidney's filtration system.
• If body temp. is too low, blood capillaries near the surface restrict to keep warm blood from reaching the surface and preventing heat loss.
• Assist endocrine system in delivering hormones.
How many chambers does the heart have?
Two upper (atria) and two lower chambers (ventricles).
Wall of chambers have how many layers?
epicardium: connective tissue and merges with pericardial sac.
myocardium: muscle tissue and thin layer of epithelial tissue.
What does the immune system consists of?
lymph, lymph capillaries, vessels, nodes, red bone marrow, leukocytes, white blood cells.
What do the tonsils do?
♣ located in the pharynx protect against pathogens entering the body through the mouth and throat.
Killer T cells
Memory T cells
Killer T cells
Memory T cells
• Neutrophils are short-living phagocytes that responds quickly to invaders.
• Basophils alert body of invasion.
• Killer T cells destroyed virally infected cells.
• Memory T cells remain in the blood on alert in case the invader attacks again.
• B cells produce antibodies.
Explain the two systems of the respiratory systems
♣ Divided into the upper and lower systems.
♣ Upper: nose, nasal cavity, mouth, pharynx, larynx.
♣ Lower: trachea, lungs, and bronchial tree.
Main functions of respiratory system
• Supply the body with oxygen and rid the body of carbon dioxide.
• Filters air.
• Vital for speech and cough production.
o Chemoreceptors that are located in the nasal cavity respond to airborne chemicals.
Define Acidosis and how respiratory system helps
low pH hyperventilation helps increase blood pH and carbon dioxide leaves the blood.
Define Alkalosis and how respiratory system helps
high pH - slow breathing helps lower blood pH and carbon dioxide builds up in the blood.
Role on homeostasis of respiratory system
• Carbon dioxide disassociates in the blood, forming carbonic acid.
• The amount of carbonic acid determines pH in blood.
Medulla oblongata and role in respiratory system
monitors the level of carbon dioxide in the blood and signals the breathing rate to increase when levels are too high.
Components of endocrine system
pituitary and pineal glands
thyroid and parathyroid glands
Function of posterior lobe on pituitary gland
• Two hormones:
o Antidiuretic hormone
Works with kidney to maintain water balance.
Stimulates uterine contractions during birth
Function of anterior lobe on pituitary gland
• secretes five hormones:
o human growth hormone,
o gonadotropins: controls hormones secreted by reproductive systems.
o Thyroid-stimulating hormones
Works with kidney to maintain water balance.
Function on pineal gland
secretes melatonin which helps with sleep.
Thyroid gland function
o Secretes thyroxine, triiodothyronine
Function of calcitonin
Decreases blood calcium by storing calcium in bone tissue.
How are the thyroid gland and pituitary gland interconnected
• Thyroid gland is stimulated by pituitary gland via negative feedback mechanism.
How does the parathyroid gland increase blood calcium levels?
• Parathyroid gland secretes parathyroid hormone which increases blood calcium by moving calcium from bone to blood.
Function of pancreas
• Monitors blood sugar levels but secreting two hormones: glucagon and insulin.
Function of glucagon
o Glucagon signals liver to convert glycogen to glucose and release it in the blood.
Released by alpha cells.
When blood levels are too low, what is released?
Function of insulin
o Insulin signals body to remove glucose from blood and stimulates live to uptake glucose and store it as glycogen.
Released by beta cells.
What part of the adrenal gland secretes epinephrine and norepinephrine?
role of aldosterone
works in kidney to regulate calcium and potassium concentrations and water balance in blood
Role of cortisol
helps regulate blood glucose levels, stimulates body repair, and acts as inflammatory.
Components of the Central nervous system and peripheral nervous system
CNS: brain and spinal cord.
• Brain communicates with the rest of the body via the sipinal cord.
PNS: includes nerves that branch off the brain stem.
Role of somatic and autonomic nervous systems
Somatic nervous system controls the five senses.
Autonomic nervous system controls sympathetic and parasympathetic systems.
• Sympathetic: stressful and anxiety
• Parasympathetic: returns body to normal.
Explain the reflex arc
• Simplest nerve pathway which bypasses the brain and and is controlled by the spinal cord.
• Ex. Knee-jerk response.
Role of nervous system for homeostasis
S controls the function of the internal organs, blood vessels, smooth muscle tissues, and glands.
• Sympathetic and parasympathetic systems work to balance out the stressful events.
three different types of neurons and their function
• Sensory: transmit signals to CNS and is associated with touch, pain, temperature, hearing, sight, smell, and sight.
• Interneurons: transmit signals between neurons.
• Motor: from CNS to rest of body for muscle contractions.
Components of a neuron and their function
o Cell body: contains nucleus of the neuron.
o Dendrites: receive impulses from sensory receptors.
o Axon: transmits impulses away from the cell body.
Impairs or destroys an infected individual's immune system.
As HIV advances, its final stage is AIDS, Acquired Immune Deficiency Syndrome.
Infectious viral respiratory illness.
Defective gene produces a protein causing the body to secrete mucus that is much thicker and stickier than normal.
Mucus clogs up the lungs, resulting in infections that can lead to death.
Blocks pancreas from delivering enzymes that help break down and absorb necessary nutrients from foods.
Sickle Cell anemia
Fewer red RBCs
Sickle cells are crescent-shaped and impede blood flow.
Can cause organ damage, pain, increased risk of infections.
Fatigue and/or pain
Rare genetic disorder, inherited through an autosomal recessive pattern.
Prevents an enzyme from breaking down a toxic substance, which builds up in the brain and spinal cord, which destroys neurons.
Causes seizures, loss of vision and hearing, intellectual impairment, and paralysis.
Type 1 vs Type 2 diabetes
Type 1: body fails to produce insulin
Type 2: body become insulin resistance causing high glucose blood levels.
When a zygote undergoes cell division, what does it become?
Characteristics of prokaryotes
Much smaller than eukaryotes.
Most are unicellular organisms.
No nucleus and their DNA is located in the center of the cell.
Most have cell walls.
DNA arranged in circular structure.
Lack histone proteins.
Contains only one large DNA molecule.
Characteristics of eukaryotes
Has nucleus bound by double membrane
Membrane-bound organelles that are independent of cell membrane.
Some have cell walls.
Some fungi cells contain chitin.
Some algae also contain lignin.
Effects of large surface area to volume ratio and smaller surface area to volume ratio
Prokaryotes: Because of large surface area to volume ratio, prokaryotes have high metabolic rate.
Purpose of cell membrane
Isolates cell from external environment while still allowing cell to communicate with the outside environment.
What adds stiffness and flexibility to phospholipid bilayer?
• Cholesterol adds stiffness and flexibility.
Purpose of nucleus and the components within the nucleus and their functions
Nuclear envelope: double-layer membrane with the outermost layer connected to ER.
Communicates with rest of cell through pores
Chromatin consists of DNA and histones.
Nucleolus: dense control portion of nucleus that manufactures ribosomes.
Functions: storage of genetic material, ribosome production, transcription of RNA.
Characteristics and Function of chloroplasts
Large organelles called plastids enclosed by a double membrane.
Has its own DNA and can reproduce by fission independently.
perform photosynthesis and make food in form of sugars for the plant
Processes in chloroplasts
Light reaction stage of photosynthesis occurs in grana.
Light independent reaction stage occurs in stroma.
Light reaction stage of photosynthesis occurs in grana.
Light independent reaction stage occurs in stroma.
What are the two membranes of mitochondria
Outer membrane: porins allows small molecules to go through.
Inner membrane: contains proteins that aid in ATP synthesis.
Functions of ribosomes
Consists of RNA and proteins.
Translate the DNA code into proteins through amino acid chain synthesis.
Different types of RNA
mRNA: transports a working copy of the DNA to the ribosome.
tRNA: collects the needed amino acids and delivers them to ribosome.
rRNA: assembles amino acids into the needed protein.
Function of golgi apparatus
• Packages, ships, and distributes macromolecules in shipping containers called vesicles.
Directs the movement of carbs, proteins, and lipids throughout the cell.
Modifies proteins and lipids before they're shipped.
Why are interactions between cell organelles important?
o Contacts are crucial for the synthesis and intracellular transport of phospholipids as well as intracellular homeostasis which controls contraction, motility, secretion, cell growth, proliferation, and apoptosis.
Role of carbohydrates
Provide energy as they are the body's main source of fuel.
Needed for physical activity, brain function, and operation of organs.
Intestinal health and waste elimination.
Role of lipids
Energy production and storage
Provide energy to muscles and body processes
Roles or protein
o Catalyze chemical reactions
o Synthesize and repair DNA
o Transporting materials across the cell
o Receiving and sending chemical signals.
o Structural support.
Define concentration gradient and what its caused by
♣ Differences in the concentration or the number of molecules of solutes in a solution between two regions.
♣ Caused by unequal distribution of ions across cell membrane.
Define diffusion, what affects the rate and examples of diffusion.
♣ Movement of molecules or ions down a conc. Gradient.
♣ How oxygen, CO2, other nonpolar molecules move across cell membrane.
♣ Steepness of gradient affects rate of diffusion.
Passive transport and some examples
♣ Makes use of concentration gradient and electric gradients to move substances.
♣ Molecules move across cell membrane without the cell using any energy.
♣ Ex. Diffusion and facilitated diffusion.
Active transport and an example
♣ Can move substance against concentration gradient.
♣ Molecules are forcibly moved from regions where concentration is low into a higher concentration.
♣ Carrier proteins must carry these ions and molecules.
• This requires energy.
• Sodium ions are pumped out of the cell and potassium ions are pumped out of the cell.
Define negative feedback inhibition and give an example
• Increase in an output of a reaction to a stimulus triggers a decrease in the stimulus, which leads to a decrease in the original output.
o Ex. Release of hormones insulin and glucagon to maintain blood glucose level.
Define positive feedback inhibition
• An increase in an output leads to further increase of the stimulus
What are factors influence selective permeability in cell membranes
♣ Cell size:
• Cell membrane allows only for small molecules to diffuse through it.
• Ions with like charges are repelled and ions with opposite charges are attracted to cell's surface.
Define facilitated diffusion
• Molecules are helped across a membrane by certain channel or carrier proteins
♣ These are from high to low concentrations so no energy is used.
Cells with lower concentration of water than their environment tend to rapidly gain water by osmosis
Cell with higher concentration of water than environment tend to lose water
Three processes of photosynthesis
Explain the light-capturing events of photosynthesis
• Thylakoids of chloroplasts absorb light energy and excites electrons.
o Have enzymes and electron-transport molecules.
Explain the light-dependent reactions of photosynthesis
• excited electrons are moved by electron transport in a series of steps in which they are used to split water into hydrogen and oxygen.
• Oxygen is released to create NADPH
• ATP produced form excited electrons.
Explain the light-independent reactions of photosynthesis
• Uses ATP, NADPH, and CO2 to produce sugars
Three types of photosynthesis
C3: 3C compound stores the CO2.
C4: used by plants in high light regions because it helps conserve water.
CAM: allows plants to survive long dry spells.
Three processes of cellular respiration
• Krebs Cycle:
o Net two ATP molecules by splitting a glucose which releases electrons.
Explain Krebs Cycle
o Occurs in mitochondria
o Breaks down pyruvate to release CO2 and ATP.
o Oxygen atoms are reduced by accepting electrons to produce large amounts of ATP.
Where is most of the ATP created in cellular respiration?
How much ATP?
♣ Uses oxygen and occurs in most cells.
♣ 36-38 ATP molecules released.
♣ Produces CO2, water, ATP
♣ Reactants: glucose and oxygen
♣ Does not produce ethanol and lactic acid.
How much ATP?
♣ Without oxygen and uses ETC but no oxygen as electron acceptors.
♣ Occurs in most prokaryotes
♣ Lower ATP released
♣ Products: CO2, ATP, reduced species.
♣ Reactants: glucose and electron acceptor
♣ Produces ethanol or lactic acid.
Factors that affect reaction rate of enzymes
♣ Reaction rate is affected by many factors such as temperature, pH, inhibitors.
How do different factors affect reaction rate of enzymes?
♣ Increasing temp will increase reaction rate.
♣ pH affects enzyme activity due to hydrogen ions binding to the enzyme surface and changing active site.
♣ Inhibitors care molecules that attach to enzyme and interfere with substrate.
Explain feedback inhibition
♣ The end products bind to enzymes found at the beginning of the pathway that generates that product.
• Causes reaction rate to decrease.
♣ The more product there is, the less product produced.
♣ Less product means more product is formed.
Compare mitosis and meiosis
♣ Asexual process of cell division.
♣ One parent cell divides into two identical daughter cells.
o Cell division in which the number of chromosomes are reduced in half.
o Produces gametes
o Two successive stages: two mitotic divisions.
Phases of mitosis
• Spindle fibers appear
• DNA is condensed and packaged as chromosomes that become visible.
• Nuclear membrane breaks down and nucleolus disappears.
• Spindle apparatus is formed
• Centromeres of chromosomes line up on metaphase plate
• Centromeres divide and two chromatids separate and are pulled apart.
• Spindle fibers disappear
• Nuclear membrane reforms and DNA is decondensed.
Phases or meiosis
o Meiosis I:
♣ At the end, there are two daughter cells that have the same number of chromosomes as the parent cell.
o Meiosis II:
♣ Cell enters a brief interphase but does not replicate DNA
♣ Prophase II:
• Unduplicated chromosomes split.
♣ End of telophase II:
• Four daughter cells that have half the number of chromosomes as the parent cell.
♣ Asexual reproduction without mitosis or meiosis.
♣ Division into two approximately equal parts.
Parts of interphase
♣ G1: cell increases the number of organelles by forming diploid cells.
♣ S: DN is replicated and chromosomes are doubled.
♣ G2: protein synthesis and increase in cell size.
Three checkpoints in cell cycle
♣ 1. G1/S checkpoint (called restriction):
• cell may continue division, delay division, or rest.
♣ 2. G2/M checkpoint:
• cyclin A controls this checkpoint.
♣ 3. During mitosis, checkpoint occurs at metaphase to check that the chromosomes are lined up along the metaphase plate
Components that affect gene expression
♣ Located upstream of gene needed for transcription.
♣ Promoters in Archaea and Eukaryota have TATA box which is 25 nucleotides upstream of transcription start site and is the location at which DNA is unwound.
♣ Provide binding site for proteins that either promote or inhibit RNA polymerase in transcribing proteins.
♣ Increases the expression of genes.
♣ Are upstream or inside the gene of interest.
♣ Proteins that help regulate gene expression.
♣ Binds to DNA and determines if that sequence of DNA is transcribed into mRNA.
♣ Eukaryotes: turns genes on
♣ Bacteria: turns genes off.
♣ Control gene regulation
♣ Allows cells to only code for proteins as they are needed in the cell.
• Promotes the cell to conserve energy.
What do operons consist of?
• Operator: provides binding sire for repressor that inhibits RNA polymerase binding
• Promoter: provides binding site for RNA polymerase
• Structural gene: provides the sequence that codes for a protein.
♣ Study of modifications in specific gene expression caused by factors that are not genetic.
♣ Main type of modification:
• Methylation to histones.
• Acetylation and phosphorylation
Define stem cells
♣ Undifferentiated cells that can divide without limit and differentiate to produce specialized cells.
Define pluripotent stem cells and give an example
• Have not gone through differentiation and can develop into any type of cell.
o Ex. Early embryonic stem cells.
Define multipotent stem cells
• Can only develop into few different types of cells.
♣ Somatic stem cells: adult stem cells
Different types of mutations
Point, deletions, and inversions
Different point mutations
o Missense: codes for wrong protein
o Silent: don't have function of protein
o Nonsense: stop protein synthesis early, resulting in a nonfunctioning protein.
What do deletions cause?
♣ Deletions and insertions cause a frameshift mutation in which nucleotides are grouped together incorrectly.
piece of chromosome inverts or flips orientation.
Difference between somatic and germ cell mutations
♣ Somatic: cannot be passes to offspring.
• Some are silent
• Some cause cancer or diseases.
♣ Germline: present only at conception and only in egg and sperm cells.
• Can be passed to offspring.
• Some are silent and some cause diseases.
Mendel's Law of Independent Assortment
♣ Alleles of one characteristic separate independently of the alleles of another characteristic.
• Traits are transmitted independently.
Difference between F1 and F2 generations
♣ F1 generation: offspring created from cross of initial parents.
♣ F2 generation: offspring created from cross of F1 offspring.
Law of Segregation
♣ Alleles for a trait separate when gametes are formed, which means that only one of the pair of alleles for a given trait is passed to the gamete.
♣ Situation in which one gene influences several seemingly unrelated traits.
♣ A gene that affects multiple traits.
♣ Due to normal or mutated genes.
Explain independent assortment
♣ During metaphase I of meiosis, homologous pairs align on metaphase plate.
• Orientation of pairs is random.
• Number of possible arrangements increases exponentially as the number of chromosomes increases.
♣ Can occur when two genes are located on the same chromosome.
♣ Linkage genes: genes that are located on the same chromosome and tend to be inherited together.
• Do not separate during meiosis.
Explain crossing over
♣ Exchange of equivalent segments of DNA between homologous chromosomes.
♣ Occurs during Prophase I of meiosis.
♣ Because genes have more than one allele, this allows for the exchange of genetic information.
♣ Introduces new combinations of the information that is available.
Three types of genetic exchange and explain them
• 1. Transduction: genetic material is transferred form one bacterium to another.
• 2. Transformation: cell obtains new genetic information from its environments and surroundings.
• 3. Conjugation: bacteria are in direct contact, genes can be transferred from one into the other when the two cells are joined.
for sex-linked inheritance, what chromosome is the trait on?
♣ Sex-linked traits are carried on the X-chromosome.
How can a female not have the sex-linked trait?
♣ Females may possess a recessive allele for various disorders on one X chromosome, but as long as they possess the dominant allele for normal functioning on the other X-chromosome, they will not have the disorder.
Examples of sex-linked traits
Color blindness, hemophilia, anemia, muscular dystrophy.
Explain and give examples of multiple alleles
♣ Multiple allele inheritance occurs when there are more than two different alleles of a gene for a particular trait.
• Even though there are several alleles for a particular trait, each individual can still only possess two of those possible alleles.
♣ Some genes do not have dominant or recessive alleles.
♣ Both genes for a trait are expressed in a heterozygous individual.
♣ Both phenotypes are shown.
♣ Some genes do not have dominant or recessive alleles.
♣ Both alleles are expressed, creating a mixed phenotype of the two phenotypes:
♣ White and red = pink flowers when heterozygous.
Polygenic Inheritance and examples
♣ Occurs when a trait is determined by the interaction of many different genes.
♣ Ex. Skin color and height: both have very many possible phenotypes.
Define and give example for epistasis
♣ Occurs when a gene at one locus inhibits the expression of a gene at another locus.
♣ Ex. A black mouse with genotypes BB or Bb will only have that color deposited if the pigment genotype is CC or Cc.
• Black mouse with BBcc will be white.
• Brown mouse can have bbCC or bbCc
• Mouse with bbcc will also be white.
♣ DNA always has a 1:1 ratio of purine to pyrimidine.
• Amount of adenine = amount of thymine
• Amount of guanine = amount of cytosine
What separates two strands in DNA replication?
What adds complementary bases in DNA replication?
Define Okazaki Fragments
• Short segments of DNA synthesized with lagging strand with the aid of DNA primase.
What unwinds DNA in transcription?
explain mRNA processing
• after cleavage, poly-a tail starts to form.
• mRNA strand contains one intron and two exons.
• Once spliceosome is formed, the intron is cleaved and the two exons are ligated together.
• After splicing, the remaining exons of the mRNA strand is ready for translation.
♣ tRNA has codons complementary to mRNA codons.
• tRNA binds to translation site to get correct amino acids.
• Piece of DNA breaks off and is lost without reattaching.
• Piece of DNA breaks off of one chromosome and is joined to another chromosome.
• DNA breaks off of one chromosome and becomes reattached to that same chromosome but with an inverted or flipped orientation.
• Piece of DNA is replicated and attached to the original piece of DNA in sequence.
Offspring get mitochondrial DNA from which parent?
♣ Offspring's mitochondria only come from the oocyte (egg cell), not from the sperm.
♣ Introduces new genes into an organism to correct a specific disease caused by a defective gene.
♣ Defective gene is replaced with a properly functioning one.
Genetic engineered cells
♣ Manipulation of DNA outside of normal reproduction.
♣ Called recombinant DNA
♣ Used to produce GMOs.
Problems with gene therapy
♣ Some recipients developed leukemia and the trials were halted.
• Leukemia was related to location of insertion of the retroviral vectors.
Problems with cloning
♣ Cloned mammals typically have serious health problems.
• Dolly aged prematurely due to shortened telomere from adult somatic cell nucleus.
Did DNA evolve form RNA?
No - RNA could have evolved before DNA because it can both store information and cause itself to be copied.
The three domains are based on what?
close genetic relationship between organisms based on their rRNA.
Define and give example of homologous structures
♣ Body parts that are similar in structure to other species comparative parts.
• Evidence of a common ancestor.
♣ Ex. Bird's wings, cat's legs, and human arm.
Define and give example of analogous structures
♣ Structures of different species having similar or corresponding function but not from the same evolutionary origin.
• Ex. Wings or insects and birds used for flying.
What did the fossil record prove?
• Indicates that invertebrates developed before vertebrates and fish developed before amphibians.
Explain adaptive radiation
♣ Driven by natural selection and results in new phenotypes and possibly new species.
♣ Darwin: through the process of natural selection, each type of finch adapted to the specific environment and specifically to the food sources of the island which it belonged to.
Darwin's Theory of Evolution
o Studied finches and collected 13 species with a unique bill for a distant food source.
o Darwin believed that these changes were the result from random genetic changes called mutations.
o Natural selection:
♣ Because variety exists among individuals of a species, he stated that those individuals most compete for the same limited resources.
How does mutation lead to genetic variation?
♣ Random and can benefit, harm, or have no effect.
♣ Germline mutations that occur in gametes (eggs and sperm) can be passed to offspring and therefore are very important to genetic variation and evolution.
Mutations introduce new genetic information into the genome
How does migration lead to genetic variation?
♣ Movement of organisms from one location to another.
♣ If migrating individuals mate with local individuals, there is a sudden influx in alleles.
• Alters existing population of alleles in the destination population.
How does genetic drift lead to genetic variation?
♣ Causes random changes in allele frequencies that are not a result of natural selection.
♣ Can result in loss of genetic diversity.
♣ Impacts small populations.
Bottleneck genetic drift
• Drastic reduction in population due to disaster.
• Many alleles are lost when population size is decreased.
Founder genetic drift
• When one or few individuals populate a new area such as an island.
• New population is limited to the alleles of the founds unless there is a mutation or new individuals immigrate to region.
Five conditions that must be met for HQ equilibrium
♣ (1) The population must be very large.
♣ (2) Mating is random.
♣ (3) There are no mutations.
♣ (4) No immigration or emigration can occur.
♣ (5) All individuals of the population have an equal chance to survive and reproduce
If these conditions are met, then gene frequencies will remain constant.
HW equilibirium equation and what each variable represents
• p2 + 2pq + q2 = 1
• p is the frequency of the dominant allele
• q is the frequency of the recessive allele.
• p2 is the frequency of the homozygous dominant genotype,
• 2pq is the frequency of the heterozygous genotype
• q2 is the frequency of the homozygous recessive genotype.
What does it mean if the HW equilibrium is not equal to one?
Evolution is occurring.
Equation for allele frequency
• Total # of specific alleles in a population/total # of alleles in the population for that locus.
♣ Occurs between two incipient species that become geographically isolated populations.
• For geographic reasons, two or more groups within a species cannot mate with each other.
• Can be due to volcanic eruption, desert, river.
Formation of a new distinct species
♣ Occurs when an extremely small group is geographically isolated at the edge of the rest of the population.
♣ Due to geographic distance rather than a barrier.
♣ Leads to reduced gene flow.
New species develop within a population with no geographic isolation.
♣ Occurs before fertilization and stop or hinder species from mating.
♣ Occur after fertilization but prevent hybrids from living and becoming fertile.
♣ Evolutionary changes occurred slowly or gradually by a divergence of lineages due to natural selection.
♣ Fossil records supports gradualism.
Convergent evolution and give an example
♣ Two or more unrelated species become increasingly similar in appearance.
♣ Natural selection leads to adaptation in these unrelated species belonging to the same type of environment.
• Ex. Mammals that are found in different parts of the world developed similar appearances due to similar environments.
Divergent evolution and give an example
♣ One species becomes increasingly dissimilar in appearance.
♣ As several small adaptations occur due to natural selection, the organisms will finally reach a point where two new species are formed.
• Ex. Wooly mammoth and modern elephant from common ancestor.
Independent vs dependent variable
♣ Independent variable:
• Factor that is manipulated during the experiment
♣ Dependent variable:
• Influenced by the independent variable. Factor that is being measured.
Quantitative vs Qualitative observations
♣ Quantitative: involve numbers and measurements.
♣ Qualitative: used the senses to make conclusions.
What are line and bar graphs, scatter plots, and pie charts good for?
Used when comparing parts to a whole.
Showing small or large changes over time.
Compare groups or track large changes over time.
Scatter plots used to determine if there is a correlation between two sets of data.
Name and explain the three different types of error
Random error are unpredictable because they are from an unknown cause.
Systematic errors: arise from faulty equipment and can be eliminated if identified.
Personal errors are human errors such as improper use of equipment of faulty procedures.
Percent Error equation
Percent error = experimental value - theoretical value / theoretical value x 100
Difference between accuracy and precision
¥ Accuracy is the exactness of a measurement
Expresses how close a measurement is to the actual or true value.
¥ Precision is the consistency of a measurement.
¥ Measurements are precise when they are all close together.
What is the cell theory?
♣ States that all living things are composed of cells and that cells come from pre-existing cells.
♣ Cells were first observed in 1655 by Robert Hooke.
What is the germ theory of disease?
♣ States that most infectious diseases are caused by germs or disease-causing microbes or pathogens.
♣ Foundation of microbiology and modern medicine.
♣ Pastuer discovered that yeast caused the fermentation of wine and spoiling milk.
• Discovered that weakened microbes could be used in vaccines or immunizations to prevent or protect against the diseases caused by those microbes.
Arguments for and against embyronic stem cell research
♣ Benefit: greatly alleviate suffering for many people.
♣ Cost: human embryos.
♣ Early embryo is not yet a person according to supporters and cannot survive unless it is implanted.
♣ Other argue that this type of research destroys potential life.
GM foods costs and benefits
Look at study guide
Human cloning costs and benefits
Look at study guide
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