Sexual Life Cycles and Meiosis

Flashcards covering key terminology and concepts related to sexual life cycles and meiosis, as outlined in the lecture notes.

Karyotype

A profile of an organism's chromosomes, which can reveal genetic abnormalities.

Meiosis

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

Homologous chromosomes

Pairs of chromosomes, one from each parent, that are similar in shape and size and carry genes for the same traits.

Sister chromatids

Identical copies of a chromosome, connected by a centromere, formed during DNA replication.

Tetrads

Structures that form during prophase I of meiosis when replicated homologous chromosomes pair up.

Crossing-over

The exchange of genetic material between non-sister chromatids during prophase I of meiosis.

Independent assortment

The random distribution of homologous chromosomes during meiosis.

Zygote

A fertilized egg that results from the union of sperm and egg.

Diploid

A cell that contains two complete sets of chromosomes, one from each parent (2n).

Haploid

A cell that contains a single set of chromosomes (n).

Chiasmata

The X-shaped sites where crossing-over occurs between non-sister chromatids.

Centromere

The region of a chromosome where the sister chromatids are joined.

Interphase

The phase of the cell cycle during which the cell prepares for division, including DNA replication.

Kinetochore

A protein structure on the centromere that attaches chromosomes to the spindle fibers during cell division.

Cytokinesis

The process following mitosis or meiosis, whereby the cell's cytoplasm divides to form two separate cells.

Genetic variation

Differences in DNA sequences among individuals, which can arise from processes such as meiosis.