Meiosis Flashcards
What is meiosis
Results in 4 daughter cells that are haploid ad gen different. Chromosomes in diploid exist in pairs identical in shape and genes containing same characteristics
meiotic divisions
1st meiotic div; homo pairs separate and 2 daughter cells form with 23 chromosomes each with 46 chromatids. 2nd meiotic div; chromatids separate resulting in 4 daughter cells with 23 chromosomes
Interphase 1
similar to mitosis, dna reps and each duplicated chromosome has 2 identical chromosomes
P1
Chromosomes pair off (synapsis), and chromosomes become visible, they gradually move so that members of homo pair lie along side. Homo pairs form tetrad, crossing over.
M1
Paired chromosomes move towards spindle fibres at end of p1, arrange on spindles fibres across the equator. Independent assortment occurs.
A1
Homo pairs separate, sis chromatids remain at the centromere, 23 to each side, each pole has half of og cell
T1
Uncondense, nm reappears and cytokenesis
2ND MEIOTIC DIV
Each daughter cell w/ 23 chromosomes does the same thing in which chromatids seperate and migrate to either end. 4 haploid cells
Crossing over
During P1, when homo pairs, chromatids cross, break, and exchange segments. The point at which they cross is called chiasma and results in a new como of alleles, aka recombinations