Meiosis

Question 1

Prophase

Answer 1

chromosomes condense, kinetochore and MT assemble

Question 2

Prometaphase

Answer 2

nuclear envelope breaks, MT binds kinetochore

Question 3

Metaphase

Answer 3

chromatids align a metaphase plate

Question 4

Anaphase

Answer 4

centromeres and kinetochores split, sister chromatids migrate to opposite poles

Question 5

Telophase

Answer 5

MTs and kinetochore disassemble, nuclear envelope forms and chromatids decondense

Question 6

Interphase

Answer 6

chromosomes duplicate

Question 7

Prophase I

Answer 7

bivalents join and genetic recombination occurs

Question 8

Metaphase I

Answer 8

Bivalents align at metaphase plate

Question 9

Anaphase I

Answer 9

duplicated homologs separate (sister chromatids remain attached)

Question 10

Telophase I

Answer 10

2 daughter cells result with haploid number of chromosomes, but diploid amount of DNA (1n, 2c)

Question 11

Meiosis I

Answer 11

reductive division stage

Question 12

Meiosis II

Answer 12

equational division

Question 13

Nondisjunction at meiosis I

Answer 13

results in non-separated homologous chromosomes – too many of too few homologs in daughter cells

Question 14

Nondisjunction at meiosis II

Answer 14

results in non-separated sister chromatids – too few or too many chromosomes in daughter cell

Question 15

Synaptonemal complex

Answer 15

ladder-like protein scaffold with two lateral elements and a central element; between homologs

Question 16

SYCP1

Answer 16

Central element

Question 17

SYCP2 and SYCP3

Answer 17

Lateral elements

Question 18

Mutations in SYCP1,SYCP2, and SYCP3

Answer 18

subfertility or infertility

Question 19

Leptonema

Answer 19

DSBs by SPO11, Pairing of homologs, LE forms of SC

Question 20

Zygonema

Answer 20

Synapsis, LE + CE of SC, and DSB begin repairing via non-cross-over and cross-over

Question 21

Pachynema

Answer 21

SC and synapsis complete, ALL DSBs repaired, chiasmata (1/homolog at least)

Question 22

Diplonema

Answer 22

SC breaks down, homologs separate except at chiasmata

Question 23

SPO11

Answer 23

endonuclease that creates 200-400bp DSB non-randomally throughout genome

Question 24

ALL DSBs are repaired by…

Answer 24

Pachynema of Prophase I

Question 25

2 contributions to genetic variation

Answer 25

independent assortment (2^n) and genetic recombination

Question 26

The most immature of cell of spermatogenesis is ___ and is located _____.

Answer 26

spermatogonia; basement membrane

Question 27

What cell undergoes maturation?

Answer 27

spermatid

Question 28

Spermatogonia-> primary spermatocyte-> 1st div->

Answer 28

secondary spermatocyte-> second div-> spermatid-> spermiogenesis -> spermatozoa

Question 29

Incomplete cell division/cytokinesis?

Answer 29

1. Haploid cells either have X or Y, so they share resources

2. Synchronize process

Question 30

Primary oocytes arrest in what stage?

Answer 30

dictyate state of Prophase I

Question 31

In what cell type does maturation occur?

Answer 31

Primary oocyte; until hormones trigger meiosis

Question 32

WHat step does secondary oocyte arrest at?

Answer 32

Metaphase II; until fertilization

Question 33

oogonia-> primary oocyte -> arrest Prophase I and maturation->

Answer 33

secondary oocyte-> arrest at metaphase II-> ovum