AP BIO CRAM

Cell Cycle

Ordered series of events in which a cell grows, replicates DNA, and divides.

Interphase

Includes G1, S, and G2 phases (cell growth + DNA replication).

G1 Phase

The phase where the cell grows and performs normal functions.

S Phase

The phase where DNA replication occurs, forming sister chromatids.

G2 Phase

The phase where the cell prepares for mitosis and checks for DNA damage.

M Phase

The cell division phase (mitosis + cytokinesis).

Cell Cycle Checkpoint

Control system that halts the cycle if errors occur (DNA damage, spindle issues).

CDK (Cyclin-Dependent Kinase)

Enzyme that regulates cell cycle progression by phosphorylating target proteins.

Cyclin

Protein that binds and activates CDKs.

p53

Tumor suppressor protein that triggers DNA repair, cell cycle arrest, or apoptosis.

Mitosis

Cell division producing 2 genetically identical diploid cells for growth/repair.

Prophase (Mitosis)

Chromosomes condense, nuclear envelope breaks down.

Metaphase (Mitosis)

Chromosomes align at the cell equator.

Anaphase (Mitosis)

Sister chromatids separate.

Telophase (Mitosis)

Nuclear envelopes reform.

Cytokinesis

Cytoplasm divides into two identical cells.

Meiosis

Cell division producing 4 genetically different haploid gametes.

Purpose of Meiosis

Increase genetic diversity and reduce chromosome number.

Prophase I

Homologous chromosomes pair (synapsis); crossing over occurs.

Crossing Over

Exchange of genetic material between homologous chromosomes.

Metaphase I

Homologous pairs align randomly (independent assortment).

Anaphase I

Homologous chromosomes separate.

Telophase I

Two haploid cells form.

Independent Assortment

Random distribution of homologous chromosomes into gametes.

Prophase II

Chromosomes condense again.

Metaphase II

Chromosomes align individually.

Anaphase II

Sister chromatids separate.

Telophase II

4 genetically unique haploid cells form.

DNA

Double-stranded molecule that stores genetic information.

Gene

Segment of DNA that codes for a functional product (protein or RNA).

Transcription

Process where DNA is transcribed to mRNA in the nucleus.

Translation

Process where mRNA is translated to protein at ribosome.

RNA Polymerase

Enzyme that synthesizes mRNA from DNA template.

Promoter

DNA sequence where RNA polymerase binds to start transcription.

Introns

Noncoding regions removed from pre-mRNA.

Exons

Coding regions that remain in mRNA.

Spliceosome

Complex that removes introns and joins exons.

Mutation

Change in DNA sequence.

Silent Mutation

Mutation with no change in amino acid sequence.

Missense Mutation

Mutation where one amino acid changes.

Nonsense Mutation

Mutation creating a stop codon early.

Frameshift Mutation

Mutation where insertion/deletion shifts reading frame.

Enzyme

Biological catalyst that lowers activation energy.

Active Site

Region where substrate binds to an enzyme.

Substrate

Reactant an enzyme acts on.

Denaturation

Loss of enzyme structure and function due to heat or pH change.

Competitive Inhibition

Inhibitor binds active site, increasing Km but not changing Vmax.

Noncompetitive Inhibition

Inhibitor binds allosteric site, decreasing Vmax.

Allosteric Site

Regulatory site separate from the active site.

Saturation

State where all enzyme active sites are occupied, and reaction rate plateaus.

Cellular Respiration

Process of converting glucose into ATP using oxygen.

Glycolysis

Process where glucose is converted to 2 pyruvate in the cytoplasm, producing ATP and NADH.

Pyruvate Oxidation

Conversion of pyruvate to acetyl-CoA, producing CO₂ and NADH.

Citric Acid Cycle (Krebs Cycle)

Cycle that produces CO₂, NADH, and FADH₂.

Electron Transport Chain (ETC)

Produces most ATP with oxygen as the final electron acceptor.

NADH

Electron carrier that delivers electrons to the ETC.

ATP Synthase

Enzyme that produces ATP using a proton gradient.

Photosynthesis

Conversion of light energy into chemical energy (glucose).

Light Reactions

Stage that produces ATP and NADPH, occurring in the thylakoid membrane.

Photosystem II

Part of photosynthesis that splits water and starts electron flow.

Photosystem I

Part of photosynthesis that produces NADPH.

Calvin Cycle

Process using CO₂, ATP, and NADPH to build glucose in the stroma.

Ecology

Study of interactions between organisms and the environment.

Trophic Level

Position in the food chain.

Energy Pyramid

Model showing energy decreases at higher trophic levels.

Natural Selection

Process where individuals with advantageous traits reproduce more.

Fitness

Reproductive success of an organism.

Convergent Evolution

Process where unrelated species evolve similar traits.

Homologous Structures

Body parts inherited from a common ancestor.

Allele

Alternative form of a gene.

Genotype

Genetic makeup of an individual.

Phenotype

Observable traits of an organism.

Homozygous

Individual with two identical alleles.

Heterozygous

Individual with two different alleles.

Autosomal Recessive

Trait expressed only when two recessive alleles are present.

Carrier

Heterozygous individual who does not show the disease.

Punnett Square

Diagram used to predict genetic outcomes.

MCQ Elimination Rule

Eliminate answers that are vague, absolute, or not supported by data.

Graph Interpretation Rule

State trend first, then explain biologically.

If Stuck MCQ Strategy

Choose answer with the most specific biological terminology.

FRQ Structure

Format for free response questions: Claim → Evidence → Biological reasoning.

Data Rule

Always reference numbers, trends, or comparisons in responses.

No-Answer Rule

Never leave answers blank; write related correct biology even if unsure.