Meiosis

Meiosis

a type of cell division that results in four daughter cells (gametes) each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.

Gametes

a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.

homologous chromosomes

Pair of chromosomes that are the same size, same appearance and same genes.

Haploid

having a single set of unpaired chromosomes

Diploid

having two sets of chromosomes or twice the haploid number

Chromatid

one of two identical "sister" parts of a duplicated chromosome

Prophase I (Meiosis)

Chromosomes condense, nuclear envelope fragments, spindle fibres form, homologous chromosomes pair up and form tetrads, crossing over occurs

Metaphase I (Meiosis)

Homologous chromsosome pairs are lined up at the metaphase plate; Spindle fibers attach

Anaphase I (Meiosis)

Homologous chromosomes separate. Sister chromatids remain attached at centromere.

Telophase I (Meiosis)

Nuclear envelope reassembles, spindle fibres disappear. Followed by cytokinesis

Prophase II

Chromosomes condense, nuclear envelope fragments, spindle fibres form.

Metaphase II

Chromosomes line up at the equator.

Anaphase II

sister chromatids separate and move to opposite poles

Telophase II

Nuclear membrane reforms, cytoplasm divides, 4 daughter cells formed