Biology - Cell Division and Chromosome Structure

A set of vocabulary flashcards covering key concepts about cell division and chromosome structure.

Prokaryote chromosomes

Circular molecule of DNA; replication occurs in both directions.

Eukaryote chromosomes

Linear, composed of chromatin; species have different numbers of chromosomes.

Chromatin

A complex of DNA and proteins that make up chromosomes.

Sister chromatids

Two copies of a chromosome within a replicated chromosome.

Condensation

Process where chromosomes become tightly coiled during G2 phase.

Centriole

Microtubule-organizing centers that replicate during G2.

G1 phase

Cell growth phase; first gap phase of the cell cycle.

S phase

Synthesis phase; DNA replication occurs, producing sister chromatids.

G2 phase

Second gap phase; chromosomes condense and centrioles replicate.

M phase

Mitosis phase; binary fission occurs in bacteria.

C phase

Cytokinesis; cleavage of the cell into equal halves.

Prophase

Phase where chromosomes condense and nuclear envelope breaks down.

Prometaphase

Chromosomes attach to microtubules and move towards the equator.

Metaphase

All chromosomes align at the metaphase plate, attached to opposite poles.

Anaphase

Proteins holding sister chromatids are degraded, chromosomes move to poles.

Telophase

Chromosomes cluster at poles and decondense; nuclear envelope reforms.

Cytokinesis in plant cells

Plasma membrane forms a cell plate between nuclei.

Cytokinesis in animal cells

Constricting actin filaments produce a cleavage furrow.

G1/S checkpoint

Cell decides to divide at this checkpoint.

G2/M checkpoint

Cell makes a commitment to enter mitosis at this checkpoint.

Late Metaphase checkpoint

Cell ensures all chromosomes are attached to the spindle at this checkpoint.