meiosis

Question 1

cells that will go through meiosis

Answer 1

diploid germ cells
product is haploid gametes

Question 2

Steps of meiosis

Answer 2

Interphase
G1
S
G2
Meiosis
phrophase 1
metaphse 1
anaphase 1
telophase 1
phrophase 2
metaphse 2
anaphase 2
telophase 2
Cytokinesis

1: seperate homologous chromosomes
2: seperate sister chromatids

In prophase 1: replicated chromosomes paur up to form tetrad, crossing over between homologous crhomosomes (even in XY!)

Question 3

Independent assortment

Answer 3

Chromosomes line up during methaphase 1 randomly, with respective homologous chromosoes randomly assorter to increase genetic deiveristy. Produces 4 genetically different gametes

Question 4

Sperm vs ovum

Answer 4

sperm gametes will be equally given cytoplasm
ovum gametes will have a first polar body before meiosis 2 (polar body has less cytoplasm than secondary oocyte) (will divide into 2 polar bodies) and a second polar body after cytokinesis and during differentiation, polar bodies die while ovum lives and gets fertilized. usefull as woman does not get pregrante with 4 kids at once

Question 5

nondisjunction

Answer 5

sticky chromosones at meiosis 1 or 2, will result in an aneuploidy (+/- chromosome) ex n+1
usually results in prenatal death (miscarriage), cause of down syndrom

aneuploidy especially in meiosis 2 but also meisis 1

Question 6

polyploidy

Answer 6

Condition of having multiple sets of chromosones (3n, 4n, etc) common in plants, more than 1 pair of homologous chromosomes

caused by nondisjunction of entire set of chromosomes during meiosis (ex 2n, then fetilization, +1n=3n) , 2 cells fuse into 1, fetilization of egg by more than 1 sperm, or genome duplication

Question 7

law of segregation

Answer 7

each gamete contains 1 chromosome, so 1 allele out of 2 is inherited (seperation of homologous chromosomes)