Meiosis Flashcards
(27 cards)
sexual reproduction
2 different sexes combine genetic information to produce offspring with genetic variation
gamete
cells involved in sexual reproduction
meiosis
type of cell division that produces gametes with half the amount of chromosomes in the parent cells resulting in variation
autosome
numbered chromosomes containing genes with traits for an organism
humans have 22 pairs of autosomes and 1 pair of sex cells (XX or XY)
somatic cell
all cells other than gametes (sperm and egg cells) in the body
sex chromosome
chromosomes that determine an individual’s sex
male: XY
female: XX
diploid
cell/organism with two sets of chromosomes from each parent
contains a total of 46 chromosomes in humans
haploid
cell/organism with only one set of unpaired chromosomes
contains a total of 23 chromosomes in humans
prophase I
(chromatin condenses into chromosomes) homologous chromosomes pair, crossing over
metaphase I
tetrads line up
anaphase I
chromosomes split to either side of cell by spindle fibers
telophase I
cell divides into two with sister chromatids still attatched
prophase II
seperation of sister chromatids
metaphase II
mitosis in two cells
anaphase II
sister chromatids split apart to opposite sides of cell
telophase II
cells complete division, resulting in 4 cells, one set of chromosomes each (genetically different)
cytokinesis
physically separates the two cells by dividing the cell’s organelles and cytoplasm
sister chromatids
two identical copies of a chromosome containing the same information
tetrad
group of 4 chromatids fromed during prophase I (bivalent)
homologous chromosomes
pairs of chromosomes with matching genes one from each parent
non-sister chromatids
chromatids that belong to different chromosomes in a homologous pair
crossing over
homologous chromosomes exchange genetic information making genetic variation
nondisjunction
chromosomes fail to seperate properly
karyotype
chromosomes arranged on a chart according to size, shape, and characteristics
