Meiosis

Meiosis I

First division that separates homologous chromosomes.

Meiosis II

Second division that separates sister chromatids.

Prophase I

Homologous chromosomes pair up and crossing over occurs.

Metaphase I

Homologous chromosome pairs line up at the middle.

Anaphase I

Homologous chromosomes separate and move to opposite poles.

Telophase I

Chromosomes reach the poles and the chromosome number is reduced by half.

Prophase II

Chromosomes condense and spindle fibers form again.

Metaphase II

Chromosomes line up individually at the middle.

Anaphase II

Sister chromatids separate and move to opposite poles.

Telophase II

Four haploid daughter cells are formed.

Homologous Chromosomes

Chromosome pairs with the same genes, one from each parent.

Tetrad

A pair of homologous chromosomes containing 4 chromatids.

Synapsis

Pairing of homologous chromosomes during Prophase I.

Crossing Over

Exchange of DNA between homologous chromosomes.

Recombination

Formation of new combinations of alleles through genetic exchange.

Cohesin

Protein that holds sister chromatids together.

Haploid (n)

Cell containing half the normal chromosome number.

Diploid (2n)

Cell containing two sets of chromosomes.

Gamete

A reproductive/sex cell, such as sperm or egg.