ap bio semester review

Hardy-Weinberg equilibrium

A state where allele frequencies in a population remain constant over generations in the absence of evolutionary influences.

Hardy-Weinberg formula

p + q = 1 (where p = frequency of dominant allele and q = frequency of recessive allele) and p² + 2pq + q² = 1 (where p² = frequency of homozygous dominant, 2pq = heterozygous, q² = frequency of homozygous recessive).

Darwin's Theory of Evolution

Organisms with traits that confer fitness survive and reproduce, passing those traits to offspring.

Prezygotic barriers

Reproductive barriers that prevent fertilization from occurring, such as habitat, temporal, and mechanical differences.

Postzygotic barriers

Reproductive barriers that occur after fertilization, affecting the viability or fertility of hybrid offspring.

Allopatric speciation

Speciation that occurs when populations are geographically separated.

Sympatric speciation

Speciation that occurs without geographic separation, often through behavioral or temporal barriers.

Microevolution

Small-scale evolutionary changes within a population, affecting allele frequencies.

Macroevolution

Large-scale evolutionary changes that result in the formation of new species over long periods.

Genetic drift

Random changes in allele frequencies in small populations due to chance events.

Gene flow

Transfer of alleles into or out of a population, which can reduce genetic differences between populations.

Convergent evolution

Independent evolution of similar traits in different species due to similar environmental pressures.

Divergent evolution

Evolution of species that share a common ancestor into increasingly different forms.

Homologous structures

Similar anatomical structures in different species that have different functions, indicating common ancestry.

Punctuated equilibrium

The theory that evolution occurs in rapid bursts followed by periods of stasis.

Gradual equilibrium

The theory that evolution occurs slowly and steadily over time.

Eukaryotes

Organisms whose cells contain a nucleus and membrane-bound organelles.

Prokaryotes

Single-celled organisms without a nucleus or membrane-bound organelles.

Autotroph

Organisms that create their own energy, often through photosynthesis.

Heterotroph

Organisms that obtain energy by consuming other organisms.

Hydrolysis

A chemical process that breaks down molecules by adding water.

Dehydration synthesis

A chemical process that forms new molecules by removing water.

Enzyme-substrate complex

A temporary complex formed when an enzyme binds to its substrate.

Endomembrane system

A system of membranes involved in the synthesis, modification, and transport of proteins and lipids.

Phospholipid bilayer

A structure that makes up the cell membrane, composed of hydrophilic heads and hydrophobic tails.

Diffusion

The passive movement of molecules from an area of high concentration to an area of low concentration.

Active transport

The movement of molecules across a membrane against their concentration gradient, requiring energy.

Hypotonic solution

A solution with a lower concentration of solute, causing cells to swell.

Hypertonic solution

A solution with a higher concentration of solute, causing cells to shrink.

Isotonic solution

A solution with equal concentrations of solute, resulting in no net water movement.

Mitochondria

Organelle responsible for cellular respiration and ATP production.

Chloroplasts

Organelles found in plant cells and other eukaryotic autotrophs that are the site of photosynthesis.

Nucleus

Contains the cell's genetic material (DNA) and controls cell activities.

Ribosomes

Cellular structures responsible for protein synthesis.

Photosynthesis

The process by which plants and other organisms convert light energy into chemical energy, storing it in sugar.

Light-dependent reactions

The first stage of photosynthesis, where light energy is converted into chemical energy (ATP and NADPH).

Calvin cycle

The second stage of photosynthesis, in which carbon dioxide is converted into glucose using ATP and NADPH.

Photosynthesis equation

6CO2 + 6H2O + \text{Light Energy} \rightarrow C6H{12}O6 + 6O2

Cellular Respiration

The metabolic process that breaks down glucose and other organic molecules to produce ATP.

Glycolysis

The first stage of cellular respiration, occurring in the cytoplasm, which breaks down glucose into two molecules of pyruvate.

Krebs cycle (Citric Acid Cycle)

A central metabolic pathway in cellular respiration that completes the breakdown of glucose derivatives to carbon dioxide, producing ATP, NADH, and FADH_2.

Oxidative phosphorylation

The final stage of cellular respiration, where ATP is generated through electron transport and chemiosmosis.

Cellular respiration equation

C6H{12}O6 + 6O2 \rightarrow 6CO2 + 6H2O + \text{ATP}

Cell signaling

The process by which cells communicate with each other through chemical or physical signals.

Receptor proteins

Proteins on or in a cell that bind to signaling molecules, initiating a cellular response.

Signal transduction pathway

A series of steps by which a signal from outside the cell is converted into a functional change within the cell.

Paracrine signaling

Localized cell communication where signaling molecules diffuse over short distances to nearby cells.

Endocrine signaling

Long-distance cell communication where hormones travel through the bloodstream to target cells.

Autocrine signaling

A form of cell signaling where a cell secretes a hormone or chemical messenger that binds to autocrine receptors on the same cell, leading to changes in the cell itself.