Chapter 3 meiosis

Question 1

What is the purpose of meiosis

Answer 1

to produce gametes for sexual reproduction that are genetically different

Question 2

Meiosis I:
What separates?
Centromeres (do / don’t) split

Answer 2

homologous chromosomes
dont

Question 3

Meiosis II:
What separates?
Centromeres (do / don’t) split

Answer 3

sister chromatids
do

Question 4

What are the two means of generating genetic diversity in Meiosis I?

Answer 4

1) crossing over
2) Independent assortment

Question 5

_______ of alleles is illustrated by the behavior of two pairs of homologues during meiosis

Answer 5

Independent assortment

Question 6

What are the 5 stages of prophase I in meiosis?

Answer 6

1) leptotene
2) zygotene
3) pachytene
4) diplotene
5) diakinesis

Question 7

Pairing and recombination of homologs takes place in _______

Answer 7

prophase I

Question 8

What happens in leptotene? (3)

Answer 8

1) chromosome condensation begins
2) centrosomes begin to move
3) aster forms

Question 9

What happens in zygotene? (4)

Answer 9

1) chromosomes still condense, and centrosomes still migrate
2) synapsis of homologous chromosomes
3) mitotic spindle form
4) nuclear envelop breakdown begins

Question 10

_______ (protein bridge) forms between homologous chromosomes as they align

Answer 10

synaptonemal complex

Question 11

What happens in pachytene? (2)

Answer 11

1) crossing over between nonsister chromatids
2) microtubules attach to kinetochores

Question 12

What happens in diplotene? (2)

Answer 12

1) synaptonemal complex dissolves
2) chiasma present

Question 13

What happens in diakinesis? (2)

Answer 13

1) nuclear envelop completely dissolves
2) tetrads move towards middle of cell

Question 14

Paired homologs are called _______

Answer 14

tetrads

Question 15

_______ form at intervals in the synaptonemal complex. These are aggregates of enzymes and proteins needed for crossing over.

Answer 15

recombination nodules

Question 16

During metaphase I _______ align on opposite sides of the metaphase plate

Answer 16

homologs

Question 17

kinetochore microtubules attach to _______ sister chromatids of one homolog pair

Answer 17

both

Question 18

anaphase I begin when homologs _______ from one another

Answer 18

separate

Question 19

in telophase I, the _______ briefly reforms around the separated haploid sets of chromosomes and creates two ________ cells

Answer 19

nuclear membrane
haploid

Question 20

Meiosis I is called the _______ because the ploidy of the daughter cells is halved compared to the original diploid parent cell

Answer 20

reductional division

Question 21

Meiosis II divides each haploid daughter cell into two _______ cells by separating sister chromatids from one another. The process is similar to mitosis in a haploid cell.

Answer 21

haploid