Lecture 18: Meiosis

Question 1

inhibitors of microtubules

Answer 1

taxol, paclitaxel, nocodazole, vinblastine (all toxic )

Question 2

inhibitors of microfilaments

Answer 2

cytochalasin, phallodin

Question 3

steps of meiosis

Answer 3

Interphase (G1, S, G2), Prophase 1, Metaphase 1, Anaphase 1, Telophase 1 and Cytokinesis 1, Prophase 2, Metaphase 2, Anaphase 2, Telophase 2 and Cytokinesis 2

Question 4

Meiosis I is like

Answer 4

the business side of meiosis (separating homologous chromosomes)

Question 5

Meiosis II is like

Answer 5

mitosis (separating sister chromatids)

Question 6

Prophase I (Meiosis)

Answer 6

Centrosome movement along with spindle fiber formation
- Nuclear envelope dissolves
- Chromosomes condense
- Homologous chromosomes pair up and cross over genetic material
- Microtubules attach to kinetochores of each homologous pair (move them to methaphase plate)

Question 7

Metaphase I (Meiosis)

Answer 7

Tetrads are lined up (homologous chromosomes) at the metaphase plate; Spindle fibers attach
- independent assortment

Question 8

Anaphase I (Meiosis)

Answer 8

Homologous chromosomes separate

Question 9

Telophase I (Meiosis)

Answer 9

Cytoplasm divides, 2 daughter cells are formed (nucleus forms), chromosomes condense and nuclear envelope forms

Question 10

Cytokinesis I

Answer 10

cell separates into two cells

Question 11

Prophase II

Answer 11

spindle forms

Question 12

Metaphase II

Answer 12

still 2 chromosomes, 2 chromatids align at metaphase plate

Question 13

Anaphase II

Answer 13

splitting of chromatids (not sisters)

Question 14

homologous chromosomes

Answer 14

same size, contain genes at same location in the chromosome

Question 15

sister chromatids

Answer 15

replicated forms of a chromosome joined together by the centromere

Question 16

synapsis

Answer 16

pairing of replicated homologous chromosomes during prophase I of meiosis

Question 17

crossing over

Answer 17

exchange of genetic material between non-sister chromatids during synapsis in meiosis I

Question 18

chiasma

Answer 18

area/region where crossing over occurs

Question 19

mitosis vs meiosis similarities

Answer 19

both divide at the same time

Question 20

the movement of chromosomes involves

Answer 20

microtubules

Question 21

mitosis vs meiosis differences

Answer 21

synapsis only occurs in meiosis

Question 22

purpose of meiosis

Answer 22

reproduction (gametes)