Chapter 16: Cell Cycle, Mitosis, and Meiosis

Vocabulary flashcards covering the cell cycle, mitosis, meiosis, chromosome sets, and chromosomal abnormalities from Chapter 16.

Diploid cell

A cell that contains $2$ chromosome sets ($2n$).

Haploid cell

A cell that contains $1$ chromosome set ($n$).

Polyploid cell

A cell that contains $3$ or more chromosome sets.

Autosomal chromosomes

Chromosomes that do not determine biological sex. In humans, chromosomes $1 - 22$ are autosomal chromosomes.

Sex chromosomes

Chromosomes that determine biological sex. In humans, the $X$ and $Y$ chromosomes are sex chromosomes (females have $XX$ and males have $XY$).

Homologous chromosomes

Two chromosomes of the same type: one from mother and one from father (e.g., the two copies of chromosome $1$).

Interphase

The portion of the cell cycle that includes Gap 1 ($G_1$), Synthesis ($S$), and Gap 2 ($G_2$) phases.

S phase (Synthesis phase)

The stage of the cell cycle during which DNA replication occurs.

M phase

The stage of the cell cycle during which cell division occurs, consisting of mitosis and cytokinesis.

Mitosis

A process where a diploid cell divides to produce two genetically identical diploid daughter cells.

Sister chromatids

Identical copies of the same chromosome that result after chromosomes are replicated during $S$ phase of the cell cycle, remaining attached at the centromere.

Prophase/prometaphase (Mitosis)

The stage of mitosis where chromosomes condense, the nuclear envelope breaks down, and chromosomes attach to the spindle apparatus.

Metaphase (Mitosis)

The stage of mitosis where chromosomes (each composed of a pair of sister chromatids) align end-to-end on the metaphase plate.

Anaphase (Mitosis)

The stage of mitosis where sister chromatids separate to opposite poles of the cell.

Telophase and cytokinesis (Mitosis)

The stage of mitosis where the nuclear envelope re-forms, and the cytoplasm is divided to produce $2$ diploid cells.

Interphase and Mitosis Stages (Diagram Identification)

A: Metaphase; B: Interphase; C: Telophase and cytokinesis; D: Prophase/prometaphase; E: Anaphase.

Meiosis

A cell division process where a diploid cell (germ-line cell) divides to produce four haploid gametes: egg cells (females) and sperm cells (males).

Germ-line cells

Specialized gamete-producing diploid cells that undergo meiosis to produce gametes.

Bivalent

The structure composed of homologous chromosomes physically associated together, which forms during prophase I of meiosis.

Crossing-over

The process occurring during prophase I of meiosis where homologous chromosomes in a bivalent exchange genetic material, increasing genetic diversity in the population.

Metaphase I (Meiosis)

The stage of meiosis where homologous chromosome pairs (bivalents) align on the metaphase plate.

Anaphase I (Meiosis)

The stage of meiosis where homologous chromosomes are pulled to opposite poles of the cell.

Telophase and cytokinesis I (Meiosis)

The stage where the nuclear envelope reforms and cytoplasm divides to produce $2$ haploid cells with one set of chromosomes, each chromosome still composed of a pair of sister chromatids.

Metaphase II (Meiosis)

The stage of meiosis where chromosomes (each composed of a pair of sister chromatids) line up end-to-end on the metaphase plate in both haploid cells.

Anaphase II (Meiosis)

The stage of meiosis where sister chromatids separate to opposite poles of the cell.

Telophase/cytokinesis II (Meiosis)

The stage where nuclear envelopes reform in both cells, and both cells divide to produce a total of $4$ haploid cells.

Interphase and Meiosis Stages (Diagram Identification)

A: Anaphase II; B: Prophase/prometaphase I; C: Metaphase II; D: Interphase; E: Telophase and cytokinesis I; F: Prophase/prometaphase II; G: Telophase/cytokinesis II; H: Anaphase I; I: Metaphase I.

Euploid

A cell or organism whose chromosomes occur in complete sets.

Aneuploid

Cells that have an abnormal number of a particular chromosome, such that chromosomes do not occur in complete sets (i.e., having a missing copy or an additional copy).

Monosomy

A condition referring to a missing copy of a particular chromosome (e.g., Turner syndrome, where a female has only one $X$ chromosome instead of two).

Trisomy

A condition referring to an additional copy of a chromosome (e.g., trisomy $21$ or Down syndrome, where an individual has $3$ copies of chromosome $21$).