Genetics and Cell Division: Meiosis and Mitosis

These flashcards cover key vocabulary terms related to genetics, cell cycle, mitosis, and meiosis, as discussed in the lecture.

Cell Cycle

The series of events that take place in a cell leading to its division and duplication.

G1 Phase

The first gap phase in the cell cycle, lasting about 11 hours in human cells.

S Phase

The synthesis phase of the cell cycle where DNA is replicated, lasting approximately 8 hours.

M Phase

The mitotic phase of the cell cycle, lasting about 1 hour, where cell division occurs.

Meiosis

A type of cell division that reduces the chromosome number by half, producing haploid cells from diploid cells.

Homologous Chromosomes

Chromosome pairs that are similar in shape, size, and genetic content but not identical.

Alleles

Different versions of a gene that may exist for a particular trait.

Cytokinesis

The process in which the cytoplasm of a parental cell divides into two daughter cells.

Spermatogenesis

The process of sperm cell formation in males, resulting in four haploid spermatids.

Oogenesis

The process of egg cell formation in females, resulting in one viable ovum and polar bodies.

Chiasma

The point where paired chromosomes remain in contact during the first metaphase of meiosis.

Cleavage Furrow

The indentation that begins the process of cytokinesis in animal cells.

Spindle Fibers

Structures that pull chromatids apart during cell division.

Interphase

The phase of the cell cycle during which the cell spends most of its life preparing for division.

Diploid (2n)

A cell or organism that has two sets of chromosomes, one from each parent.

Haploid (n)

A cell or organism that has only one set of chromosomes.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis.

Meiosis I

The first stage of meiosis where homologous chromosomes separate.

Meiosis II

The second stage of meiosis where sister chromatids separate.

Metaphase Plate

The equatorial plane of the cell where chromosomes align during metaphase.

Nondisjunction

The failure of homologous chromosomes or sister chromatids to separate properly during cell division.

Gametes

Haploid cells that are involved in sexual reproduction.

Zygote

The fertilized egg formed by the union of two gametes.

Bivalent (Tetrad)

A pair of homologous chromosomes that are closely associated during prophase I of meiosis.