Key Terms
Meiosis solves a math problem
If fertilization doubles chromosome number every generation, something has to cut it in half first. That something is me
Haploid (n)
One set of chromosomes. Gametes are haploid.
Synapsis
Tight pairing of homologous chromosomes during prophase I.
Synaptonemal complex
The protein lattice holding homologs together during synapsis. Tetrad: a synapsed homologous pair; four chromatids total
Crossover
Exchange of DNA segments between nonsister chromatids of homologous chromosomes. Recombination nodules: protein assembli
Cohesin
Proteins holding sister chromatids together at the centromere — they stay until anaphase II. Interkinesis: brief rest be
Gamete
Haploid reproductive cell (egg or sperm). Zygote: diploid cell formed by fertilization of two gametes.
PROPHASE II
Chromosomes recondense if needed; new spindles form.
PROMETAPHASE II
Nuclear envelopes break down; each sister chromatid now has its OWN kinetochore, attaching to microtubules from opposite
CYTOKINESIS
Four haploid cells. Each has one copy of each chromosome.