Meiosis

Question 1

How many chromosomes do humans have?

Answer 1

• 23 pairs

- 46 chromosomes

Question 2

What chromosome pair represents gender?

Answer 2

23rd

Question 3

What do females have for their 23rd chromosome pair?

Answer 3

XX

Question 4

What do males have for their 23rd chromosome pair?

Answer 4

XY

Question 5

What does meiosis do?

Answer 5

reduces the no. of chromosomes

Question 6

What does meiosis produce?

Answer 6

4 gamete, haploid cells

Question 7

What are diploids denoted by?

Answer 7

2n

Question 8

What are haploids denoted by?

Answer 8

1n

Question 9

How many chromosomes do diploids have?

Answer 9

46

Question 10

How many chromosomes do haploids have?

Answer 10

23

Question 11

What are the stages of meiosis?

Answer 11

• interphase
• meiosis I
• meiosis II

Question 12

What are the stages of PROPHASE I?

Answer 12

• leptotene
• zygotene
• pachytene
• diplotene
• diakinesis

Question 13

What is MEIOSIS I?

Answer 13

• reduction/heterotypic division

- homologous chromosomes are present at the beginning

Question 14

Which takes more time, meiosis I or meiosis II?

Answer 14

meiosis I due to interphase

Question 15

Chromosomes condense and become visible

Answer 15

leptotene

Question 16

Synaptonemal complex forms and binds homologous chromosomes

Answer 16

synapsis in zygotene

Question 17

Crossing over of chromosome traits

Answer 17

pachytene

Question 18

What causes genetic variation?

Answer 18

crossing over

Question 19

Paired chromosomes begin to separate but stay attached at the chiasmata

Answer 19

diplotene

Question 20

Nuclear membrane disintegrates

Answer 20

diakinesis

Question 21

Alignment of the sister chromosomes at the center of the cell

Answer 21

metaphase I

Question 22

Nuclear membrane is completely disintegrated

Answer 22

metaphase

Question 23

Tetrads line up at the metaphase plate

Answer 23

metaphase I

Question 24

What’s another word for the metaphase plate?

Answer 24

equatorial plate

Question 25

Tetrads are pulled apart by spindle fibers and pulled to opposite poles

Answer 25

anaphase I

Question 26

Sister chromatids at the opposite poles start to decondense

Answer 26

telophase I

Question 27

Spindle fibers disappear

Answer 27

telophase I

Question 28

2 non-identical daughter cells are produced

Answer 28

cytokinesis I

Question 29

What is MEIOSIS II?

Answer 29

• equational division

- individual chromosomes are present in the beginning

Question 30

Decondensed chromatids condense again

Answer 30

prophase II

Question 31

Nuclear envelope disintegrates again to let chromosomes align

Answer 31

prophase II

Question 32

Sister chromatids align at the metaphase plate

Answer 32

metaphase II

Question 33

Spindle fibers pull sister chromatids apart

Answer 33

anaphase II

Question 34

Non-kinetochore spindle fibers grow longer and extend the cell

Answer 34

anaphase II

Question 35

4 non-identical daughter cells are produced

Answer 35

cytokinesis II

Question 36

Similarities between mitosis and meiosis

Answer 36

• preceded by interphase
• common pathway (PMAT)
• cytokinesis

Question 37

What are HOMOLOGOUS CHROMOSOMES?

Answer 37

• 1 tetrad with one hormone from each parent

- same size and gene type

Question 38

What is a TETRAD?

Answer 38

group of four chromatids

Question 39

What is a SYNAPTONEMAL COMPLEX?

Answer 39

protein structure between homologous chromosomes

Question 40

What is the CHIASMA? (pl. chiasmata)

Answer 40

point of attachment of recombinant chromatids

Question 41

What does RECOMBINANT mean?

Answer 41

produced by shuffling of genetic info

Question 42

What is INTERKINESIS?

Answer 42

centrosome replicates before entering equational division

Question 43

What is NONDISJUNCTION?

Answer 43

failure to separate the homologous chromosomes/sister chromatids

Question 44

What does nondisjunction cause?

Answer 44

genetic disorders