Prevent the hybrid zygote from becoming a fertile adult.
reduced hybrid viability
When the genes of different species interact and impair hybrid development.
reduced hybrid fertility
Sterile hybrids due to uneven chromosome number.
Hybrid is fertile, but when they breed next generation sterile.
When a population is divided; leads to speciation.
speciation without a divided population.
In plants, the result of extra set of chromosomes during cell division.
Having more than two sets of chromosomes from a single species.
Evolution of many new species from a common ancestor as a result of introduction to new environments.
New species change most as it buds from a parent species and then changes little for the rest of its existence.
A model of evolution in which gradual change over a long period of time leads to biological diversity.
Change in the rate or timing of a developmental event; an organism's shape depends on relative growth rate of body parts.
Proportioning that gives a body a specific form.
Determine basic features of where a body part is.
Class of homeotic genes. Changes in these genes can have profound impact on morphology.
Begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product.
Metabolic pathways that release energy by breaking down complex molecules into simpler compounds.
Metabolic pathways that consume energy to build complicated molecules from simpler ones.
Kinetic energy associated with the random movement of molecules or atoms.
Occurs when an object is not moving, but may still posses energy.
first law of thermodynamics
Energy can be transferred and transformed, but it cannot be created or destroyed
A measure of disorder or randomness.
second law of thermodynamics
Every energy transfer or transformation increases the entropy of the universe.
Gibbs free energy
Measures the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell.
Reaction that absorbs free energy from its surroundings.
Reaction that proceeds with a net release of free energy.
The use of an exergonic process to drive an endergonic one.
ATP (adenosine triphosphate)
Composed of a sugar ribose, nitrogenous base adenine, and a chain of three phosphate groups bonded to it.
The metabolic process of introducing a phosphate group into an organic molecule.
Flow of energy through an animal. Limits its behavior, growth, reproduction.
Amount of energy an animal uses in a unit of time, and the sum of all the energy-requiring biochemical reactions.
Animals that are warmed mostly by heat generated by metabolism.
Animals that gain heat mostly from external sources.
"Steady state" or "constant internal milieu".
An animal that uses internal control mechanisms to moderate internal change in the face of external fluctuation.
An animal that allows its internal condition to vary with certain external changes.
Organism that obtains energy from the foods it consumes.
Process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates.
Organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds.
Organisms that use light as a source of energy to synthesize organic substances.
Green pigment located within the chloroplasts.
Microscopic pores in the leaf which lets carbon dioxide in and oxygen out. Also where water is lost.
Stack of thylakoids.
Fluid inside the chloroplast where the Calvin Cycle happens.
Flattened membranes in the chloroplast where the light reactions take place.
Part of photosynthesis that involves light. ATP and NADPH are produced. Takes place on the thylakoid membrane.
Molecules that absorb, reflect, or transmit light.
A cluster of pigments embedded into a thylakoid membrane.
In the thylakoid membranes of a chloroplast during light-dependant reactions, two molecules of water are split to form oxygen, hydrogen ions, and electrons.
Process of adding a phosphate group.
The initial incorporation of carbon into organic compounds.
Carbon fixation process in photosynthesis. Forms sugar and other organic compounds.
A graph plotting a pigment light light absorption.
A profile of the relative performance of the different wavelengths in photosynthesis.
The only pigment that can participate directly in the light reactions.
Accessory pigments that broaden the spectrum of colors that can drive photosynthesis.
The reaction center chlorophyll in the photosystem II.
The reaction center cholophyll in the photosystem I.
The location of the first light driven chemical reaction of photosynthesis.
primary electron acceptor
Specialized molecule that traps a high energy electron before it can return to ground state in the chlorophyll.
Process by which protons are pumped into the thylakoid membrane. Protons passively flow through the ATP synthase, which leads to the synthesis of ATP.
The most abundant protein on earth. Performs Carbon Fixation in the Calvin Cycle.
A partial degradation of sugars that occur without the use of oxygen.
When oxygen is consumed as a reactant along with the organic fuel.
electron transport chain
Breaks the fall of electrons to oxygen in several energy-releasing steps.
Breaking glucose into two molecules of a compound called pyruvate.
Completes the breakdown of glucose by oxidizing a derivative of pyruvate to carbon dioxide.
When energy is released at each step of the chain is stored in a form the mitochondrion can use to make ATP.
When an enzyme transfers a phosphate group from a substrate molecule.
Is formed when pyruvate first enters into the mitochondria via active transport.
The enzyme that make ATP from ADPand inorganic phosphate.
When energy is stored in the form of a hydrogen ion gradient across a membrane which is used to drive cellular work.
Emphasizes the capactiy of the gradient to preform work.
Occurs by fermentation, which generate ATP solely by substrate-level phosphorylation.
When pyruvate is converted to ethanol in 2 steps.
lactic acid fermetation
When pyruvate is reduced directly by NADH to form lactic as am end product, with no release of carbon dioxide.
Bacteria that can make enough ATP to survive using fermentation or respiration.
Carbon dioxide and water vapor in atmosphere trap infrared radiation, re-reflecting it back toward earth.
The circulation of chemicals necessary for life, from the environment, through organisms, and back to the environment.
Sewage and fertilizer runoff adds nutrients to lakes; phytoplankton decreases and cyanobacteria increases.
The amount of added nutrient that can be absorbed by plants without damaging ecosystem.
Molecule with partial charges. Mixes with water.
No partial charges. Do not mix with water.
Attraction of an atom for electrons in a covalent bond.
Water molecules sticking to each other.
Water molecules sticking to other surfaces.
Something dissolved in a solution.
Dissolving agent of a solution.
The heat required to raise the temperature of one gram of a substance one degree centigrade.
heat of vaporization
The heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas at the same temperature.
heat of fusion
The heat absorbed by a unit mass of a solid at its melting point in order to convert the solid into a liquid at the same temperature.
The property of a liquid whereby the surface becomes cooler during evaporation, owing to a loss of highly kinetic molecules to the gaseous state.
a solution in which water is the solvent
The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition.
When a substance moves from an area of higher concentration to an area of lower concentration. Due to entropy.
The diffusion of water through a selectively permeable membrane.
The diffusion of small solutes through a selectively permeable membrane.
Transport of a substance across a cell membrane by diffusion. Going with a concentration gradient.
When a cell gets materials or excretes them by using its own energy, usually through ATP; going against a concentration gradient.
Describes a solution that has a greater concentration of total solute.
Describes a solution that has a lesser concentration of total solute.
Describes solutions that have an equal concentration of total solutes.
The pressure inside of a cell as a cell pushes itself against the cell wall.
This happens when a cell shrinks inside its cell wall while the cell wall remains intact.
This happens when water moves, but the amount within the cell is constant; no pressure builds.
A cell with a cell wall that has a reasonable amount of pressure but is healthy.
This happens when a cell swells until pressure bursts it, resulting in cell death.
This happens when a cell shrinks and shrivels; can result in cell death if severe.
The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.
This measurement has a maximum value of 0; it decreases as the concentration of a solute increases.
This measurement has a minimum value of 0 (when the solution is open to the environment); it increases as pressure increases.
A property of a plasma membrane that allows some substances to cross more easily than others.
Molecules are said to be this when it has regions that are both hydrophilic and hydrophobic.
fluid mosaic model
Structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer.
Transmembrane proteins with hydrophobic regions that completely span the hydrophobic interior of the membrane.
Integral proteins that span the membrane.
The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.
An exchange of molecules (and their kinetic energy and momentum) across the boundary between adjacent layers of a fluid or across cell membranes.
A protein built into the membrane with active site exposed.
The function of membrane proteins in which some glycoproteins serve as ID tags that are recognized by membrane proteins of other cells.
Membrane carbohydrates that are covalently bonded to lipids.
Membrane carbohydrates that are covalently bonded to proteins.
A membrane protein that is responsible for moving hydrophilic substances from one side to the other.
A membrane protein, specifically a transport protein, that has a hydrophilic channel that certain molecules or atomic ions use as a tunnel.
A membrane protein, specifically a transport protein, that facilitates the passage of water through channel proteins.
A membrane protein, specifically a transport protein, that holds onto molecules and changes their shapes in a way that shuttles them across the membrane.
A difference in the concentration of a substance across a distance.
The ability of a solution to cause a cell to gain or lose water; depends partly on concentration of nonpenetrating solutes relative to inside of cell.
The control of water balance.
Passive diffusion that is aided by transport proteins, but that does not require cellular energy.
The voltage of a plasma membrane.
The combination of forces that acts on membrane potential.
A protein channel in a cell membrane that opens or closes in response to a particular stimulus.
An electrogenic pump that works largely with H+ ions.
The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.
Occurs when a cell secretes certain biological molecules by the fusion of vesicles with the plasma membrane.
Occurs when a cell takes in biological molecules and particulate matter by forming new vesicles from the plasma membrane.
Process in which extensions of cytoplasm surround and engulf large particles and take them into the cell.
A type of endocytosis in which the cell "gulps" droplets of fluid into tiny vesicles.
Double membrane perforated with pores that control the flow of materials in and out of the nucleus.
A netlike array of protein filaments lining the inner surface of the nuclear envelope; it helps maintain the shape of the nucleus.
A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.
Small membrane-bound sac that functions in moving products into, out of, and within a cell.
Synthesis of lipids, phospholipids and steroid sex hormones, and helps detoxify drugs and toxins.
A network of interconnected membranous sacs in a eukaryotic cell's cytoplasm; covered with ribosomes that make membrane proteins and secretory proteins.
A protein with one or more carbohydrates covalently attached to it.
Vesicles in transit from one part of the cell to another.
Stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum.
A cell organelle that contains digestive enzymes.
A membranous sac that helps move excess water out of the cell.
A microbody containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.
Strong layer around the cell membrane in plants, algae, and some bacteria.
"Steady state" or "constant internal milieu".
A type of regulation that responds to a change in conditions by initiating responses that will counteract the change. Maintains a steady state.
A type of regulation that responds to a change in conditions by initiating responses that will amplify the change. Takes organism away from a steady state.
Process of maintaining an internal temperature within a tolerable range.
Increases in the diameter of superficial blood vessels; cools the body.
Reduces blood flow and heat transfer by decreasing the diameter of superficial blood vessels.
Plant hormone that promotes leaf abscission and fruit ripening.
type 1 diabetes mellitus
Diabetes in which no beta-cell production of insulin occurs and the patient is dependent on insulin for survival.
type 2 diabetes mellitus
Diabetes in which the body produces insulin, but not enough, or there is insulin resistance. The patient usually is not dependent on insulin for survival.
A physiological cycle of about 24 hours that is present in all eukaryotic organisms and that persists even in the absence of external cues.
A physiological response to photoperiod, the relative lengths of night and day. An example of photoperiodism is flowering.
A class of light receptors in plants. Mostly absorbing red light, these photoreceptors regulate many plant responses, including seed germination and shade avoidance.
critical night length
The number of hours of darkness that determines whether or not a plant will flower.
A plant that flowers only when the light period is longer than a critical length. Usually spring or early summer.
A plant that flowers only when the light period is shorter than a critical length. Usually fall or winter.
A plant whose flowering is not affected by photoperiod.
Growth of a plant shoot toward or away from light.
Indoleacetic acid (IAA), a natural plant hormone that has a variety of effects, including cell elongation, root formation, secondary growth, and fruit growth.
Physiological state in which activity is low and metabolism decreases.
long-term torpor that is an adaptation to winter cold and food scarcity
Summer torpor. Enables animals to survive long periods of high temperatures and scarce water supplies.
In small mammals and birds, daily lowering of metabolism that allows them to survive on stored energy.
Relatively long-distance movement of individuals, usually on a seasonal basis.
A simple change in activity or turning rate in response to a stimuli.
Automatic, oriented movement toward or away from some stimuli.
The phenomenon whereby somatic cells, bacteria, and other organisms direct their movements according to certain chemicals in their environment.
Immunity that is present before exposure and effective from birth. Responds to a broad range of pathogens.
Immunity that is present only after exposure and is highly specific.
White blood cells.
Protein that is produced by lymphocytes and that attaches to a specific antigen.
The most abundant type of white blood cell. Phagocytic and tend to self-destruct as they destroy foreign invaders, limiting their life span to a few days.
A group of about 30 blood proteins that may amplify the inflammatory response, enhance phagocytosis, or directly lyse extracellular pathogens.
Protein produced by cells in response to being infected by a virus; helps other cells resist the virus.
Innate response with the purpose of containing a site of damage, localizing the response, eliminating the invader and restore tissue function.
Chemical stored in mast cells that triggers dilation and increased permeability of capillaries.
natural killer (NK) cells
These cells kill cancer cells and cells infected with viruses. They bind to their targets and deliver a lethal burst of chemicals to produce holes in the target cell's membrane leading to its destruction.
Any foreign molecule that is specifically recognized by lymphocytes and elicits an immune response.
Small, accessible portion of an antigen that can be recognized.
B lymphocytes (B cells)
Lymphocyte that matures in the bone marrow and secretes antibodies.
T lymphocytes (T cells)
Lymphocyte that matures in the thymus and acts directly against antigens in cell-mediated immune responses.
The process by which an MHC molecule binds to a fragment of an intracellular protein antigen and carries it to the cell surface, where it is displayed and can be recognized by a T cell.
Gland in the thoracic cavity above the heart where T lymphocytes mature.
General term for lymphocytes that are responsible for immunological memory and protective immunity.
primary immune response
Immune response the first time the body is exposed to a particular antigen. Does not peak until 10-17 days after exposure.
secondary immune response
Immune response after the body has already been exposed to a specific antigen. Response is faster, of greater magnitude, and more prolonged.
humoral immune response
The branch of acquired immunity that involves the activation of B cells and that leads to the production of antibodies.
cell-mediated immune response
The branch of acquired immunity that involves the activation of cytotoxic T cells, which defend against infected cells.
helper T cells
Activate macrophages, B cells and T cells.
A form of acquired immunity in which the body produces its own antibodies against disease-causing antigens.
Immunity conferred by transferring antibodies from an individual who is immune to a pathogen to another individual.
B cell receptor
The antigen receptor on B cells: a Y-Shaped, membrane-bound molecule consisting of two identical heavy chains and two identical light chains.
T cell receptor
Antigen receptors on a T cell. Unlike antibodies, T cell receptors are never produced in a secreted form.
Major histocompatibility compex (MHC)
Binds to a fragment of an antigen within a cell and presents it on the surface of the membrane.
cytotoxic T cells or "killer T cells"
T cells that directly attack infecting organisms; these cells attack antigen labeled foreign or host tissue.
The living parts of an ecosystem.
The nonliving parts of an ecosystem.
The phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another.
A surface-coating colony of one or more species of prokaryotes that engage in metabolic cooperation.
A close and often long-term interaction between two or more different species.
Symbiotic relationship in which both species benefit from the relationship.
Symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed.
Symbiotic relationship in which one organism lives in or on another organism, called the host, and consequently harms it.
Parasites that live within the body of their host.
Parasites that feed on the external surface of a host.
A type of parasitism in which an insect lays eggs on or in a living host; the larvae then feed on the body of the host, eventually killing it.
An abnormal condition that affects the body of an organism.
An organism that causes disease.
A widespread outbreak of an infectious disease.
An interaction in which one organism kills another for food.
Any animal that lives by preying on other animals.
An animal hunted or caught for food.
Camouflage that makes a predator or prey difficult to spot.
The bright coloration of animals with effective physical or chemical defenses that acts as a warning to predators.
A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators.
A type of mimicry in which two or more unpalatable species resemble each other.
Number of individuals per unit area.
Network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem.
An immediate increase in the amount of algae and other producers that results from a large input of a limiting nutrient.
A pore found in the epidermis of leaves, stems and other organs that is used to control gas exchange.
A membranous sac formed by phagocytosis of microorganisms or particles to be used as food by the cell.
A single opening that takes in nutrients and exchanges gases with the environment.
In insects, a system of branched, air-filled tubes that extends throughout the body and carries oxygen directly to cells.
In insects, openings on the abdomen and thorax through which air enters and waste gases leave the body.
In insects, narrow tubes branching from trachea and making direct contact with cells to facilitate gas exchange.
Membranous tube with cartilaginous rings that conveys inhaled air from the larynx to the bronchi.
Two short branches located at the lower end of the trachea that carry air into the lungs.
Small passageways by which the air passes from the bronchi to the air sacs of the lungs.
Tiny sacs of lung tissue specialized for the exchange of gases between air and blood.
positive pressure breathing
A breathing system used by amphibians in which air is forced into the lungs.
negative pressure breathing
A breathing system in which air is pulled into the lungs when the lung volume is expanded.
An excretory system, such as the flame bulb system of flatworms, consisting of a network of tubules lacking internal openings.
In flatworms, specialized cells that remove excess water from the body.
In annelid worms, a type of excretory tubule with internal openings that collect body fluids and external openings that excrete waste from the body.
Organ in vertebrates that removes urea, excess water, and other waste products from the blood and passes them to the ureter.
The functional unit of the kidney.
Combination of evaporation and transpiration.
The increasing concentration of a harmful substance in organisms at higher trophic levels in a food chain.
An insecticide that is also toxic to animals and humans.
Native to a certain area.
Species introduced to new areas that often disrupt the indigenous communities.
Slang for hydraulic fracturing- a process that removes natural gas from shale.
Breakup of a habitat into smaller pieces, usually as a result of human activities.
A phagocytic cell present in many tissues that functions in both specific and nonspecific immunity.
Immune cells that circulate within the hemolymph of insects and ingest foreign substances by phagocytosis.
In insects, combined blood and lymph.
pattern-recognition receptors (PRRs)
Proteins expressed by cells of the innate immune system that evolved before adaptive immunity.
Molecules associated with groups of pathogens that are recognized by cells of the innate immune system.
systemic acquired resistance (SAR)
A "whole-plant" resistance response that occurs following an earlier localized exposure to a pathogen.
The point during development at which a cell becomes committed to a particular fate due to cytoplasmic effects or to induction by neighboring cells.
The process by which a cell becomes specialized for a specific structure or function.
Diploid cell resulting from the union of a haploid egg and a haploid sperm.
All cells in an organism contain the same complement of genes. These are the same set of genes that are established in the fertilized egg.
Cells that are able to develop into any type of cell found in the body.
Able to give rise to multiple, but not all, cell types.
Making a genetically identical copy of DNA or of an organism.
A technique in which the nucleus of one cell is placed into another cell that already has a nucleus or in which the nucleus has been previously destroyed.
Using a somatic cell from a multicellular organism to make one or more genetically identical individuals.
Unspecialized cell that can both reproduce itself indefinitely and differentiate into specialized cells of one or more types.
The process by which an organism takes shape and the differentiated cells occupy their appropriate locations.
Maternal substances in egg that influence the course of early development.
The process by which neighboring cells can influence the determination of a cell.
Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.
Genes that determine basic features of where a body part is.
Class of homeotic genes. Changes in these genes can have a profound impact on morphology.
The development of a spatial organization of tissues and organs.
Small, non-coding RNA molecules that function in regulation of gene expression by binding to and destabilizing target mRNAs.
Programmed cell death.
Growth of a plant shoot toward or away from light.
A plant's response to seasonal changes in length of night and day.
The 24-hour biological cycles found in humans and many other species.
The ability of bacteria to sense the presence of other bacteria via secreted chemical signals.
A behavior that is developmentally fixed.
Summer torpor. Enables animals to survive long periods of high temperatures and scarce water supplies.
Differentiation of niches that enables similar species to coexist.
Symbiotic association between a fungus and a photosynthetic partner, usually green algae or cyanobacteria.
A symbiotic association between a fungus and the roots of a plant.
The process in reproduction and growth by which a cell divides to form daughter cells.
The ordering of genes in a haploid set of chromosomes of a particular organism.
A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size.
Any of the cells of a plant or animal except the reproductive cells.
Threadlike structures made of DNA molecules that contain the genes.
The readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins.
Identical copies of a chromosome; full sets of these are created during the S subphase of interphase.
The region of the chromosome that holds the two sister chromatids together during mitosis.
In animal cells, a cytoplasmic organelle that organizes the mitotic spindle fibers during cell reproductions.
Series of events that cells go through as they grow and divide.
Cell division in which the nucleus divides into nuclei containing the same number of chromosomes.
Mitosis and cytokinesis.
The cell cycle is directed by these internal controls.
Replication of DNA during S-phase of interphase.
Alignment of chromosomes prior to separation.
Separation of chromosomes.
Division of the cytoplasm to form two separate daughter cells.
Period of the cell cycle between cell divisions.
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.
The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.
The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.
When a cell specializes, it often enters into a stage where it no longer divides, but it can reenter the cell cycle when given appropriate cues.
Disease that results from disruptions of cell cycle control.
An assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis.
A structure in animal cells containing centrioles from which the spindle fibers develop.
Connects the centrosome with the kinetochore in the centromere region of the chromosome.
A specialized region on the centromere that links each sister chromatid to the mitotic spindle.
Microtubules and fibers that radiate out from the centrioles.
Plane midway between the two poles of the cell where chromosomes line up during metaphase.
The first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate.
A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.
density dependent inhibition
The arrest of cell division that occurs when cells grown in a laboratory dish touch one another.
Regulatory proteins that ensure that the events of cell division occur in the proper sequence and at the correct rate.
Complex of cyclin and kinase.
A cyclin-Cdk complex that causes the cell to move from interphase into mitosis.
The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane; specifically.
One of the alternative forms of a gene that governs a characteristic, such as hair color.
alteration of generations
The alteration of two or more different forms in the life cycle of a plant or animal.
Chromosomes that are not directly involved in determining the sex of an individual.
One parent produces a genetically identical offspring by mitosis.
X-shaped regions where crossing over occurred.
Nonsister chromatids exchanging DNA segments.
Has two sets of chromosomes.
Union of gametes.
A haploid cell such as an egg or sperm that unite during sexual reproduction to produce a diploid zygote.
Units of heredity made up of DNA.
One set of chromosomes.
Pair of chromosomes that are the same size, same appearance and same genes.
Photograph of chromosomes grouped in order and in pairs.
All of the events in the growth and development of an organism until the organism reaches sexual maturity.
The specific site of a particular gene on its chromosome.
Random errors in gene replication that lead to a change in the sequence of nucleotides; the source of all genetic diversity.
Different chromatids (maternal and paternal) of the same chromosome.
Chromosomes that carry genes from each parent. http://o.quizlet.com/Hk486OhrBK7sHtaml1nnmg.png
X and Y chromosomes.
When two parents give unique combination of genes to offspring.
Homologous chromosomes pair up, aligned gene by gene.
A pair of chromosomes form tetrads made up of four chromatids.
Fertilized egg; carries one set of chromosomes from each parent.
Is demonstrated by the differences in appearance that offspring show from parents and siblings.
platelet-derived growth factor (PDGF)
One of the numerous proteins that regulate the cell cycle.
law of independent assortment
The random distribution of the pairs of genes on different chromosomes to the gametes.
law of segregation
Allele pairs separate or segregate during gamete formation, and randomly unite at fertilization. Due to separation of homologous chromosomes in Meiosis I.
A heritable feature that varies among individuals.
Each variant of a character.
Organisms that, when reproducing, create offspring of all the same variety.
The crossing of two different true-breeding parents.
The name for the true-breeding parents.
The hybrid offspring of true-breeding parents.
After the self-pollenization, of the F1 generation, this is produced.
The Law of Segregation
Two alleles separate during gamete formation and end up in different gametes because they are on homologous chromosomes.
An allele whose trait always shows up in the organism when the allele is present.
An allele that is masked when a dominant allele is present
A diagram for predicting the allele composition of offspring from a cross between individuals of known genetic makeup.
An organism having a pair of identical alleles for a character, either dominant or recessive.
An organism's traits.
An organism's genetic makeup.
The result of breeding a recessive homozygote with an organism of dominant phenotype but unknown genotype.
Parents that are heterozygous for one character.
Parents that are heterozygous for two characters.
To determine the probability, we multiply the probability of one event by the probability of another.
Considering mutually exclusive events, the probability of both occurring is the sum of the probabilities of each event.
When the phenotypes of the heterozygote and dominant homozygote are indistinguishable.
When which the phenotypes of both alleles are exhibited in the heterozygote.
Creates a blended phenotype; one allele is not completely dominant over the other.
A diagram that shows the occurrence of a genetic trait in several generations of a family.
A genetic disorder that is present at birth and affects both the respiratory and digestive systems.
chorionic villus sampling CVS
Prenatal diagnostic technique that involves taking a sample of tissue from the chorion.
A fetal test in which amniotic fluid from a pregnant woman is extracted to aid in the diagnosis of fetal abnormalities.
A failure of paired homologous chromosomes to separate during meiosis which results in an abnormal chromosome number.
Down syndrome (trisomy 21)
A genetic disorder caused by the presence of all or part of a third copy of chromosome 21.
A genetic disorder in which there is at least one extra X chromosome to a standard human male karyotype,
A human genetic disease caused by a recessive allele that leads to the accumulation of certain lipids in the brain. Seizures, blindness, and degeneration of motor and mental performance usually become manifest a few months after birth.
Genetic disorder that causes progressive deterioration of brain cells. caused by a dominant allele. symptoms do not appear until about the age of 30.
Genetic disorder in which red blood cells have abnormal hemoglobin molecules and take on an abnormal shape.
When the heterozygote genotype has a higher relative fitness than either the homozygote dominant or homozygote recessive genotype.
Human Genome Project (HGP)
The international scientific research project with the goal of determining the sequence of base pairs in human DNA and identifying and mapping the total genes of the human genome.
Genes located on the same chromosome that tend to be inherited together in genetic crosses.
The regrouping of genes in an offspring that results in a genetic makeup that is different from that of the parents.
Offspring with a phenotype that matches one of the parental phenotypes.
Offspring who have inherited new combinations of genes and have phenotypes that don't match either parental phenotypes.
Process in which homologous chromosomes exchange portions of their chromatids during meiosis.
An ordered list of the genetic loci along a particular chromosome.
A genetic map based on recombination frequencies.
A measurement of the distance between genes; one map unit is equivalent to a 1 percent recombination frequency.
Traits are the product of multiple genes and/or physiological processes.
Traits that vary continuously (such as height or weight).
A sex determination system in which females have two of the same kind of sex chromosome and males have two different ones.
Either of a pair of chromosomes that combine to determine the sex and sex-linked characteristics of an individual.
sex linked genes
Genes located on the sex chromosomes.
X linked genes
Genes found on the X chromosome.
A dense body formed from a deactivated X chromosome.
Variation in phenotype depending on whether an allele is inherited from the male or female parent.
When expression of a gene depends on the sex of the individual.
A phenotypic difference between males and females of the same species.
Occurs when genes that are not part of a nuclear chromosome are passed on from parent to offspring.
A gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.
A unit of genetic function common in bacteria and phages, consisting of coordinately regulated clusters of genes with related functions.
A protein that binds to DNA and stimulates transcription of a specific gene.
A specific small molecule that inactivates the repressor in an operon.
Region of DNA that controls RNA polymerase's access to a set of genes with related functions.
Nucleotide sequences that allow the genes of an operon to be transcribed.
Nucleotide sequences that mark the end of a gene or operon.
A protein that suppresses the transcription of a gene.
Short regions of DNA that can be bound with proteins to enhance transcription.
An example of a repressible operon.
An example of an inducible operon.
An operon under negative control. It is usually "on" but can be turned "off".
An operon under positive control. It is usually "off" but can be turned "on".
Proteins that bind to specific DNA sequences or other regulatory proteins that promote or block RNA polymerase.
Normal somatic cells will become growth inhibited when they encounter another cell.
A diverse group of soluble molecules which act as hormonal regulators or signaling molecules and help in cell signaling.
Y linked gene that triggers the male sexual development pathway in animals.
Plant hormones in the seed embryo that signal starch hydrolysis during germination.
Signaling molecules that stimulate cell differentiation and development.
Molecule that prevents mitosis in cells with damaged DNA. Changes in its activity can result in cancer.
The process by which a signal on a cell's surface is converted into a specific cellular response.
These regulators influence cells in the vicinity of them.
Circulating chemical signals that are formed in specialized cells, travel in body fluids, and act on specific target cells.
A molecule that specifically binds to another molecule, often a larger one.
The enzyme that transfers phosphate groups from ATP to protein.
Activated by a G-protein. Converts ATP to cyclic AMP in response to an extracellular signal.
Enzymes that can rapidly remove phosphate groups from proteins.
Small, non-protein water soluble molecules or ions that send messages throughout the cells by diffusion.
inositol triphosphate (IP3)
Produced by cleavage of a certain kind of phospholipid in the plasma membrane.
The target cell's detection of a signal molecule coming from outside the cell.
The binding of the signal molecule changes the receptor protein in some way.
The transduced signal finally triggers a specific cellular response.
A plasma membrane receptor that works with the help of a G-protein.
receptor tyrosine kinase (RTK)
A receptor with enzymatic activity that can trigger more than one signal transduction pathway at once, helping the cell regulate and coordinate many aspects of cell growth and reproduction.
ligand-gated ion channel
Type of membrane receptor that has a region that can act as a "gate" when the receptor changes shape.
A second messenger produced by the cleavage of a certain kind of phospholipid in the plasma membrane.
cyclic AMP (cAMP)
secondary messenger that activates protein kinases and initiates phosphorylation cascades.
An open channel in the cell wall of plants through which strands of cytosol connect from adjacent cells.
In animal cells, pores formed from connected membrane proteins that allow molecules to pass directly from cell to cell.
Type of cell signalling where cells communicate over short distances by using local regulators that target cells in the vicinity of the emitting cell.
Type of cell signalling where signals released by one cell type can travel long distances to target cells of another cell type.
A hormone released by the anterior pituitary that targets all cells in the body. Stimulates whole body growth in children and adolescents, and increases cell turnover rate in adults.
thyroid stimulating hormone (TSH)
Hormone made by the anterior pituitary that regulates the production of T3 and T4 hormones produced by the thyroid gland.
change in shape
A neurotransmitter that, among its fuctions, triggers muscle contraction.
A behavior that causes a change in another animal's behavior.
The reception of and response to signals.
Behavior performed correctly and in the same way by all individuals of a species, without previous experience.
A behavior that has been learned from experience or observation.
A type of relationship in which mating occurs with no strong pair-bonds or lasting relationships.
A type of relationship in which one male mates with one female.
A type of relationship in which one male mates with many females.
A type of relationship in which one female mates with many males.
When members of one sex choose mates on the basis of particular characteristics.
A direct competition among individuals of one sex for mates of the opposite sex.
optimal foraging theory
The basis for analyzing behavior as a compromise of feeding costs versus feeding benefits.
Behavior that tends to increase the fitness of the individual and the survival of the population.
Central Nervous System (CNS)
Includes the brain and spinal cord.
Peripheral Nervous System (PNS)
The sensory and motor neurons that connect the CNS to the rest of the body.
Contains most of a neuron's organelles and its nucleus.
highly branched extensions that receive signals from other neurons
Long nerve fiber that conducts away from the cell body of the neuron.
The junction between two neurons or between a neuron and a muscle.
Chemical messengers that cross the synaptic gaps between neurons.
The transmitting neuron in a synapse.
The neuron, muscle, or gland cell that receives the signal from a neuron.
The voltage across a cell's plasma membrane.
The membrane potential of a neuron that is at rest.
The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.
voltage-gated ion channels
Channels that open or close in response to a change in the membrane potential.
A neural impulse; a brief electrical charge that travels down an axon.
Return of the cell to resting state, caused by reentry of potassium into the cell while sodium exits the cell.
The minimum membrane potential that must be reached in order for an action potential to be generated.
A layer of electrical insulation that surrounds the axon.
Type of glial cell in the CNS that wrap axons in a myelin sheath.
Type of glia in the PNS, Supporting cells of the peripheral nervous system responsible for the formation of myelin.
nodes of Ranvier
Gaps in the myelin sheath to which voltage-gated sodium channels are confined.
Membrane-bounded compartments in which synthesized neurotransmitters are kept.
The narrow gap that separates the presynaptic neuron from the postsynaptic cell.
Common vertebrate neurotransmitter, especially in neuromuscular junctions.
A neurotransmitter that affects hunger,sleep, arousal, and mood.
A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.
Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline.
A precursor of epinephrine that is secreted by the adrenal medulla and also released at synapses.
An inhibitory neurotransmitter in the brain.
The most common neurotransmitter in the brain. Excitatory.
Natural analgesics that decrease pain perception.
Structural and functional unit of nervous system.
Muscle cells or gland cells that carry out the body's response to stimuli.
Provide structural and metabolic support for neurons.
Cells in the nervous system that support, nourish, and protect neurons.
Whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths.
The portions of the central nervous system that are abundant in cell bodies of neurons rather than axons. Unmyelinated.
autonomic nervous system
the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles and heart and glands
Largest part of the brain; responsible for voluntary muscular activity, vision, speech, taste, hearing, thought, and memory.
The largest and most complicated region of the brain, including the thalamus, hypothalamus, limbic system, and cerebrum.
Region between the hindbrain and the forebrain; it is important for hearing and sight.
The posterior portion of the brain including the cerebellum and brainstem.
Interconnected neural cells that covers the cerebral hemispheres; the body's ultimate control and information-processing center.
The oldest part and central core of the brain, responsible for automatic survival functions.
The "little brain" attached to the rear of the brainstem that helps coordinate voluntary movement and balance.
Major input center for sensory information going to the cerebrum and the main output center for motor information leaving the cerebrum.
The right and left halves of the cerebrum.
a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell.
Carbohydrate component of plant cell walls.
Storage polysaccharide of plants.
Extremely branched polymer of glucose.
Polysaccharide found in arthropod exoskeletons.
Suffix of a sugar.
Made of 4 rings of carbon.
Steroid common in cell membranes, also in many hormones.
Bonds that connect amino acids.
Reinforce tertiary structure.
Chain of amino acids.
Either an alpha helix or beta pleated sheet.
Results from interactions between side chains.
Results from 2 or more polypeptide subunits.
Suffix of a protein.
Bonds between phosphate group and pentose sugar in nucleic acids.
To put together.
To break apart.
Condensation reaction where molecules are connected by loss of a water molecule.
Breaking down complex molecules by the chemical addition of water.
Another name for dehydration synthesis.
Another term for R-group. A variable group that determines the unique chemical properties of a particular amino acid.
A spiral shape constituting one form of the secondary structure of proteins, arising from a specific hydrogen-bonding structure.
beta pleated sheet
One form of the secondary structure of proteins in which the polypeptide chain folds back and forth, held together by hydrogen bonds.
Protein molecules that assist the proper folding of other proteins.
saturated fatty acids
A fatty acid in which all carbons are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton.
unsaturated fatty acids
A fatty acid possessing one or more double bonds between the carbons. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton.
A simple sugar that is the basic subunit of a carbohydrate.
A covalent bond formed between two monosaccharides by a dehydration reaction.
Flattened, membrane-bound compartments that make up the Golgi apparatus.
All cells in an organism contain the same complement of genes. These are the same set of genes that are established in the fertilized egg.
The number of different species in a community.
The number and relative abundance of species in a community.
Growth of a population in an ideal, unlimited environment, represented by a J-shaped curve.
Growth pattern in which a population's growth rate slows or stops following a period of exponential growth, forming an S-shaped curve.
carrying capacity (K)
Maximum population of a particular species that a given habitat can support over a given period.
Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.
density dependent factors
A limiting factor of a population wherein large, dense populations are more strongly affected than small, less crowded ones.
density independent factors
Limiting factor that affects all populations in similar ways, regardless of population size.
Also called density-independent selection. Characterized by many offspring with little or no parental care.
Also called density-dependent selection. Characterized by few offspring with little or much parental care.
type I survivorship
Usually experience high survival in early and middle life, followed by a rapid decline in later life. Usually K-selected
type II survivorship
Experience roughly a constant mortality rate regardless of age. Prey animals such as birds can follow this pattern of survival.
type III survivorship
Experience the greatest mortality early on in life, with relatively low rates of death for those surviving. Usually r-selected.
A model used in population geography that describes the ages and number of males and females within a given population.
Found that organic molecules can form in a strongly reducing atmosphere.
Aggregates of abiotically produced molecules surrounded by a membrane.
Membrane-bound droplets that form when lipids are added to water.
Oldest known fossils. Many layers of bacteria and sediment.
Ancestors of mitochondria and plastids was prokaryotes thatcame to live in a host cell.
Sequence of endosymbiotic events that led to ancestral eukaryote.
Horizontal gene transfer between different bacteria and archae.
Collections of autonomously replicating cells.
RNA world hypothesis
Hypothesis that describes how the Earth may have been filled with RNA-based life before it became filled with the DNA-based life we see today.
RNA molecules that function as catalysts.
vertebrate animals having four feet, legs or leglike appendages.
Motion of continents about Earth's surface on plates of crust floating on the hot mantle.
A supercontinent that included all the landmass of the earth prior to the Triassic period, when it split into Laurasia and Gondwanaland.
Still in existence.
Last Universal Common Ancestor (LUCA)
Hypothetical early cell, or group of cells, that gave rise to all subsequent life on Earth.