Lecture on Meiosis and Sexual Life Cycles

A set of vocabulary flashcards based on the key concepts of meiosis and sexual life cycles.

Meiosis

A process of cell division that reduces the number of chromosomes in gametes from diploid to haploid.

Gametes

Haploid cells (sperm or egg) that fuse during fertilization to form a diploid zygote.

Diploid

A cell that contains two sets of chromosomes, one from each parent, denoted as 2n.

Haploid

A cell that contains one set of chromosomes, denoted as n.

Karyotype

An ordered display of the pairs of chromosomes from a cell.

Homologous chromosomes

Pairs of chromosomes that are the same length and shape and carry genes controlling the same inherited characters.

Independent assortment

The process during meiosis where homologous chromosomes orient randomly at metaphase I, leading to genetic variation.

Crossing over

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

Sex chromosomes

Chromosomes that determine the sex of an individual; in humans, these are X and Y chromosomes.

Sporophyte

The multicellular diploid stage in the life cycle of plants that produces haploid spores by meiosis.

Gametophyte

The multicellular haploid stage that develops from spores and produces gametes.

Zygote

The diploid cell resulting from the fusion of two haploid gametes.

Meiosis I

The first meiotic division, which separates homologous chromosomes.

Meiosis II

The second meiotic division, which separates sister chromatids.

Chiasmata

X-shaped regions formed during crossing over where nonsister chromatids exchange genetic material.

Cleavage furrow

The structure that forms during cytokinesis in animal cells, aiding in the division of the cytoplasm.