Tuesday Apr 8, 2025 Meiosis

Chromosome

Structural units of the genome that carry genetic information.

Diploid

A cell that contains two complete sets of chromosomes, one from each parent.

Homologous chromosomes

A pair of chromosomes that contain the same set of genes, but may have different alleles.

Somatic cells

Any cells of the body that are not gametes (sex cells).

Germ cells

Cells involved in reproduction (gametes), such as sperm and eggs.

Mitosis

A type of cell division that results in two genetically identical daughter cells.

Meiosis

A specialized type of cell division that produces haploid gametes from diploid cells.

Gametes

Haploid reproductive cells (sperm and eggs) that fuse during fertilization.

46 total chromosomes

The total number of chromosomes in human diploid cells, consisting of 23 pairs.

Genetic diversity

Variability in the genetic makeup of individuals, which contributes to evolution.

Crossing over

The exchange of genetic material between homologous chromosomes during prophase I of meiosis.

Synapsis

The pairing of homologous chromosomes during meiosis.

Nuclear division

The process by which a cell divides its nucleus, as in mitosis or meiosis.

Sister chromatids

Identical copies of a single chromosome, connected at the centromere.

Maternal homolog

The chromosome inherited from the mother.

Paternal homolog

The chromosome inherited from the father.

Meiotic spindle

The structure that separates chromosomes during meiosis.

Telophase I

The final stage of meiosis I where the nuclear envelope re-forms around the separated homologs.

Haploid gametes

Reproductive cells that contain only one set of chromosomes.

Prophase I

The first stage of meiosis I where homologous chromosomes pair and recombination occurs.

Metaphase I

The stage during meiosis when homologous chromosomes line up at the metaphase plate.

Anaphase I

The stage of meiosis I when homologous chromosomes are pulled apart to opposite poles.

Cytokinesis

The final step in cell division where the cytoplasm divides, resulting in two separate cells.

Prophase II

The stage in meiosis II where chromosomes condense again and the nuclear envelope breaks down.

Metaphase II

The stage in meiosis II when chromosomes line up at the metaphase plate.

Anaphase II

The stage in meiosis II when sister chromatids are separated.

Telophase II

The final stage of meiosis II where nuclei reform around each set of chromosomes.

Recombinant chromatids

Chromatids that have undergone crossing over and have a mix of paternal and maternal DNA.

Non-recombinant chromatids

Chromatids that have not undergone crossing over and are identical to the parental chromosome.

Interphase

The phase of the cell cycle where DNA is replicated before cell division.

Bivalent

A structure formed during prophase I when two homologous chromosomes align closely.

Random orientation

The random arrangement of homologous chromosomes or chromatids during cell division.

Evolutionary innovation

The emergence of new traits in a population, often driven by genetic variation.