AP Biology Exam Review Flashcards

polar

Molecule with partial charges. Mixes with water.

nonpolar

No partial charges. Do not mix with water.

electronegativity

Attraction of an atom for electrons in a covalent bond.

cohesion

Water molecules sticking to each other.

adhesion

Water molecules sticking to other surfaces.

solute

Something dissolved in a solution.

solvent

Dissolving agent of a solution.

isomers

Same atoms but different arrangement.

alpha glucose

Monomer for starch and glycogen.

beta glucose

Monomer for cellulose and chitin.

cellulose

Carbohydrate component of plant cell walls.

starch

Storage polysaccharide of plants.

glycogen

Extremely branched polymer of glucose.

chitin

Polysaccharide found in arthropod exoskeletons and fungal cell walls.

tryiacylglycerol

Glycerol and three fatty acids.

steroids

Made of four rings of carbon.

cholesterol

Steroid common in cell membranes, also in many hormones.

peptide bond

Bonds that connect amino acids.

disulphide bridges

Reinforce tertiary structure.

primary structure

Chain of amino acids.

secondary structure

Either an alpha helix or beta pleated sheet.

tertiary structure

Results from interactions between side chains.

quaternary structure

Results from two or more polypeptide subunits.

purines

Bases with a double-ring structure.

pyrimidines

Bases with a single-ring structure.

phosphodiester bonds

Bonds between phosphate group and pentose sugar in nucleic acids.

synthesis

To put together.

digestion

To break apart.

dehydration synthesis

Condensation reaction where molecules are connected by loss of a water molecule.

hydrolysis

Reaction where water split into two hydrogens and one oxygen; this breaks a polymer.

anabolism

Metabolic pathways that construct molecules, requiring energy.

catabolism

Metabolic pathways that break down molecules, releasing energy.

natural selection

A population can change over time if individuals with more fit traits leave more offspring than less fit individuals.

evolutionary adaptation

An accumulation of inherited characteristics that enhance organisms' ability to survive and reproduce in specific environments.

artificial selection

Humans modifying species for desired traits through selective breeding.

fitness

Individuals whose inherited traits confer an advantage have a better chance of surviving in a given environment and will leave more offspring.

homology

Similarity resulting from common ancestry.

homologous structures

Same structure, different function. Comes from common ancestor.

comparative embryology

Embryos of vertebrates share many anatomical homologies.

vestigial structures

Are little or no importance to organism, but remain from an ancestor.

biogeography

Geographic distribution of species.

microevolution

Change in genetic makeup of a population from generation to generation.

macroevolution

Evolutionary change above the species level.

population

Group of individuals of the same species living in the same area.

population genetics

Study of allele frequency distribution and change under the influence of evolutionary processes.

gene pool

All the genes in a given population at a given time.

allele frequency

Proportion of an allele in a gene pool.

Hardy-Weinberg Theorem

Helps measure changes in allele frequencies over time. Provides an "ideal" population to use as a basis of comparison.

mutation

Changes in the nucleotide sequence in DNA.

sexual recombination

Crossing over and shuffling of genes during meiosis.

genetic drift

Change in allele frequencies due to chance.

bottleneck effect

When a population has been dramatically reduced, and the gene pool is no longer reflective of the original population's.

founder effect

When a small number of individuals colonize a new area; the new gene pool is not reflective of original population.

gene flow

When a population gains or loses alleles., movement of alleles into or out of a population due to the migration of individuals to or from the population.

genetic variation

Heritable variations in a population.

geographic variation

Difference in variation between population subgroups in different areas.

cline

A graded change in a trait along a geographic axis.

relative fitness

Fitness of a particular genotype.

directional selection

Shift toward a favorable variation.

disruptive selection

Shift toward the extremes.

stabilizing selection

Shift that favors the mean.

heterozygous advantage

Maintains recessive alleles in a population,

sexual selection

Natural selection for mating success.

sexual dimorphism

Differences between the sexes in secondary sexual characteristics.

speciation

Origin of new species and the source of biological diversity.

biological species concept

Species is a group of populations whose members have the potential to produce fertile offspring.

reproductive isolation

Barriers that impede members of two different species fro producing fertile offspring.

prezygotic barriers

Barriers that impede mating or hinder fertilization.

habitat isolation

When two species encounter each other only rarely.

temporal isolation

When two species breed at different times of day, season, or years.

behavioral isolation

Incompatible courtship rituals, pheromones, or bird songs.

mechanical isolation

Morphological differences prevent fertilization.

gametic isolation

When sperm can't fertilize the eggs.

postzygotic barriers

Barriers that 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 breakdown

Hybrid is fertile, but when they breed the next generation is sterile.

allopatric speciation

When a population is divided; leads to speciation.

sympatric speciation

Speciation without a divided population.

polyploidy

In plants, the result of an extra set of chromosomes during cell division.

autopolyploid

Having more than two sets of chromosomes from a single species.

allopolyploid

Sterile hybrid is changed to a fertile polyploid due to mutation; fertile with each other, but not parent species.

adaptive radiation

Evolution of many new species from a common ancestor as a result of introduction to new environments.

punctuated equilibrium

A model of evolution in which a new species will change the most as it buds from a parent species, and then will change little for the rest of its existence.

gradualism

A model of evolution in which gradual change over a long period of time leads to biological diversity.

heterochrony

Change in the rate or timing of a developmental event; an organism's shape depends on relative growth rate of body parts.

allometric growth

Proportioning that gives a body a specific form.

homeotic genes

Genes that determine basic features of where a body part is.

Hox genes

Class of homeotic genes. Changes in these genes can have a profound impact on morphology.

phylogeny

Evolutionary history of a species or group of species.

analogy

Anatomical similarity due to convergent evolution.

homoplasies

Analogous structures that have evolved independently.

taxonomy

A classification of organisms into groups based on similarities.

phylogenetic trees

Branching diagrams that depict hypotheses about evolutionary relationships.

cladogram

Diagram that shows patterns of shared characteristics.

clade

A taxonomic grouping that includes only a single ancestor and all of its descendants.

cladistics

A phylogenetic classification system that uses shared derived characters and ancestry as the sole criterion for grouping taxa.

monophyletic group

A taxonomic grouping that includes an ancestral species and all of its descendants.

paraphyletic group

A monophyletic group in which some descendants of the common ancestor have been removed.

polyphyletic group

A taxonomic grouping consisting of several species that lack a common ancestor (more work is needed to uncover species that tie them together into a monophyletic clade).