Cell Division Flashcards
What is an autosome
A non-sex chromosome
How many chromosomes are there in a normal somatic cell?
46 (22 pairs of autosomes and 2 sex chromosomes)
What is mitosis?
Diploid 2N cell replicates it’s DNA to form a diploid 4N cell and divides to form two identical 2N daughter cells
What is meiosis?
Diploid 2N cell replicates it’s DNA to form a 4N diploid cell which undergoes two cell divisions (meiosis 1 and 2) to form 4 haploid 1N cells (gamete)
In males, how many spermatozoa are produced from meiosis of 1 germ cell?
4 spermatozoa (4 haploid cells)
In females, how many oocytes are yielded from a single germ cell?
1 haploid oocyte with 3 non functional, small haploid polar bodies
What are the phases of interphase?
G1, synthesis, G2
What are the phases of m phase?
Mitosis and cytokenesis
What are the phases of mitosis?
Prophase, métaphase, anaphase, telophase
What happens in prophase?
Chromosomes condense, nuclear envelop dissolves, miroirs spindle fibers form
What happens in metaphase?
Chromosomes align at the equator of the cell
What happens in anaphase?
The chromosomes split to opposite poles of the cell
What happens in telophase?
Last phase of mitosis, the nuclear envelope forms around the chromosomes in preparation for cytokenesis
What happens in prophase 1?
Chromosomes condense and pair (leptotene), synapsis of chromosomes (zygotene) gene swapping (patchytene) meisosis arrests until puberty in women (diplotene) and continues after puberty forming the spindle fibres required for metaphase (diakenesis)
