Cell Cycle and Mitosis

Flashcards summarizing key terms and concepts related to the cell cycle, mitosis, and meiosis.

Interphase

The phase of the cell cycle where the cell grows, duplicates its DNA, and prepares for mitosis. It includes G1, S, and G2 phases.

Mitosis

A process of nuclear division that produces two identical nuclei with the same genetic content as the parental cell.

Cytokinesis

The process that divides the cytoplasm of a parent cell into two daughter cells.

G1 phase

The first stage of interphase where the cell grows and carries out normal metabolism; organelles duplicate.

S phase

The phase of interphase where DNA replication and chromosome duplication occur.

G2 phase

The second growth phase of interphase, where the cell prepares for mitosis.

Cohesin

The protein complex responsible for holding sister chromatids together after DNA replication.

MPF (Maturation-Promoting Factor)

A protein complex that triggers entry into the M phase; composed of a kinase and cyclin.

Checkpoints

Regulatory points in the cell cycle that ensure proper completion of key processes before the cell proceeds.

Anaphase

The stage of mitosis when sister chromatids separate and move toward opposite poles.

Telophase

The final stage of mitosis where the daughter cells return to interphase, nuclear envelopes reassemble, and chromosomes disperse.

Plant Cell Division

The process involving unique features such as the formation of a cell plate and building a new extracellular wall during cytokinesis.

Meiosis

A type of cell division that reduces the chromosome number by half and leads to the production of gametes.

Prophase I

The first stage of meiosis where chromosomes condense, homologous chromosomes pair, and genetic recombination occurs.

Homologous chromosomes

Chromosome pairs consisting of one chromosome from each parent that are similar in shape and size.

Telophase I

The stage of meiosis I where less dramatic changes occur, and the nuclear envelope may or may not reform.

Gametic meiosis

Meiosis occurring during gamete formation, typical in animals, producing gametes from germ cells.

Sporic meiosis

Meiosis occurring in plants, where spores develop into gametophytes.

Zygotic meiosis

Meiosis occurring immediately after fertilization, forming haploid spores that undergo mitosis.

Karyotype

A photograph or diagram that shows the complete set of chromosomes in an organism, used to analyze chromosome numbers and structure.

Crossing over

The process during Prophase I of meiosis where homologous chromosomes exchange genetic material, leading to genetic diversity.

Tetrad

A structure containing four chromatids formed during meiosis consisting of a pair of homologous chromosomes.

Nondisjunction

An error in meiosis or mitosis where chromosomes fail to separate properly, leading to gametes with an abnormal number of chromosomes.

Diploid

A cell or organism that has two complete sets of chromosomes, one from each parent, typically represented as 2n.

Haploid

A cell or organism that has a single set of chromosomes, typically represented as n, as seen in gametes.

Somatic cells

Any cell of a living organism except for the reproductive cells; they are diploid in humans.

Gametes

Reproductive cells (sperm and eggs) that are haploid and unite during fertilization to form a diploid zygote.

Fertilization

The process by which a sperm cell merges with an egg cell, resulting in the formation of a zygote.

Zygote

The fertilized egg resulting from the union of gametes, which will develop into a new organism.