Meiosis

Question 1

Synapsis

Answer 1

during early prophase 1 homologous chromosomes become “zipped up”

Question 2

synaptonemal complex

Answer 2

proteins responsible for “zipping up” chromosomes

Question 3

Crossing over

Answer 3

genetic recombination btwn non sister chromatids

Question 4

chiasmata

Answer 4

site of crossing over, contact maintained until anaphase 1

Question 5

Steps of crossing over

Answer 5

1. ) condensation
2. ) synapsis
3. ) crossing over and chiasmata formation
4. ) partial separation of homologs

Question 6

Prophase I

Answer 6

chiasmata present

Question 7

Prometaphase I

Answer 7

spindles attach to kinetochores on chromosomes

Question 8

Metaphase I

Answer 8

homologous pairs line up in center

Question 9

Anaphase I

Answer 9

homologous chromosomes separate, but sister chromatids don’t

Question 10

Telophase I & Cytokinesis

Answer 10

daughter cells ready for prophase II

Question 11

Prophase II

Answer 11

nuclear envelop breaks down, chromosomes condense

Question 12

Prometaphase II

Answer 12

spindles attach to kinetochores on chromosomes

Question 13

Metaphase II

Answer 13

chromosomes align in center of cell

Question 14

Anaphase II

Answer 14

sister chromatids separate

Question 15

Telophase II & Cytokinesis

Answer 15

nuclear envelope reforms and the cytoplasm divides

Question 16

What’s the Principle of Independent Assortment?

Answer 16

the random separation of homologous chromosomes during meiosis I that results in a variety of combinations or maternal and paternal chromosomes

Question 17

What does crossing over produce?

Answer 17

genetic diversity btwn homologous chromosomes, new combos of alleles on the same chromosome, and combinations that did not exist in each parent

Question 18

nondisjunction

Answer 18

if both homologs or both sister chromatids move to the same pole of the parent cell (fail to separate)

Question 19

Trisomy 21

Answer 19

47, +21 (Down Syndrome)

Question 20

Turner Syndrome

Answer 20

45, X

Question 21

Klinefelter syndrome

Answer 21

47, XXY

Question 22

Jacobs Syndrome

Answer 22

47, XYY