Interphase, Meiosis 1.&.2

G1

Cell grows, performs normal functions, makes proteins and organelles.

S phase

phase

G2

Cell grows more, checks copied DNA, prepares division machinery.

Prophase I

homologous chromosomes pair by synapsis, form tetrads, and exchange DNA through crossing over.

Prometaphase I

the nuclear envelope breaks down and spindle fibers attach to tetrads.

Metaphase I

homologous chromosome pairs line up randomly at the metaphase plate, causing independent assortment.

Anaphase I

homologous chromosomes separate while sister chromatids remain attached.

Telophase I

chromosomes reach opposite poles, and each pole has a haploid set of duplicated chromosomes.

Cytokinesis I

Cytoplasm divides, two cells form, each cell is haploid.

Prophase II

chromosomes condense and spindle fibers form, but there is no crossing over or homologous pairing.

Prometaphase II

spindle fibers attach to individual chromosomes so they can line up single file.

Metaphase II

chromosomes line up single file at the metaphase plate.

Anaphase II

sister chromatids separate and move to opposite poles.

Telophase II

nuclei reform around haploid sets of chromosomes.

Cytokinesis

Cytoplasm divides, four haploid cells form, each is genetically different.