Meiosis

Question 1

How many stages of Meiosis are there? What are they?

Answer 1

2. Meiosis I and Meiosis II

Question 2

What happens before Meiosis I?

Answer 2

All chromosomes duplicate

Question 3

What happens to the nuclear membrane during Prophase I?

Answer 3

It breaks down

Question 4

What happens w/ the spindle fibers during Prophase I?

Answer 4

They start to form

Question 5

What happens in Prophase I with the replicated chromosomes?

Answer 5

Each replicated chromosome joins with its pair to form a group of four sister chromatids

Question 6

What is the group of chromosomes formed in Prophase I called?

Answer 6

A tetrad

Question 7

What is the pairing process that forms tetrads in Prophase I called?

Answer 7

Synapsis

Question 8

What may happen to the homologous chromosomes while the chromosomes are in tetrad formation?

Answer 8

Twist around each other and exchange segments of chromosomes

Question 9

What is the segment exchange between chromosomes during synapsis called?

Answer 9

crossing over

Question 10

What happens to the chromosomes during Metaphase I?

Answer 10

They line up in the center of the cell in tetrad formation

Question 11

What happens to the spindle fibers during Metaphase I? Where?

Answer 11

They attach to the tetrads at their centromeres

Question 12

What is disjunction?

Answer 12

When the homologous pairs separate and move to opposite sides of the cell.

Question 13

When does disjunction happen?

Answer 13

Anaphase I

Question 14

The two cells that result from Meiosis I are diploid or haploid?

Answer 14

Haploid

Question 15

Why does the cell need to divide again after Meiosis I?

Answer 15

Because the chromosomes are each still double stranded.

Question 16

What happens during Telophase I and Cytokinesis?

Answer 16

The cell divides into two new, haploid cells

Question 17

How many chromosomes do the two cells that resulted from Meiosis I have?

Answer 17

Half the number of chromosomes as the original

Question 18

What happens during Prophase II?

Answer 18

Each daughter cell forms spindle fibers and the chromosomes move toward the middle of the cell

Question 19

What happens during Metaphase II?

Answer 19

The chromosomes line up in the center, one by one, of both daughter cells and the spindle fibers attach to their centromeres

Question 20

What happens during Anaphase II?

Answer 20

The two chromatids separate, each becoming a single stranded chromosome and they move to opposite sides of the cell

Question 21

What happens to the nuclear membrane during Telophase II/Cytokinesis?

Answer 21

It reforms

Question 22

What happens to the cells during Telophase II/Cytokinesis?

Answer 22

They divide, forming 4 haploid cells

Question 23

What happens to the chromosomes during Telophase II/Cytokinesis?

Answer 23

They change back to chromatin

Question 24

Where do gametes develop?

Answer 24

The gonads

Question 25

What are the female gonads and gametes?

Answer 25

Ovaries, and egg cells, or ova

Question 26

What are the male gonads and gametes?

Answer 26

Testes, sperm

Question 27

What is gametogenesis?

Answer 27

the process by which gametes develop in the gonads

Question 28

What is oogenesis?

Answer 28

the process of ovum formation which occurs in the ovaries

Question 29

What is a hermaphrodite?

Answer 29

Organisms in which there is no separate male or female gender. they have both testes and ovaries

Question 30

Examples of hermaphrodite organisms

Answer 30

Earthworms, snails, and other slow moving organisms

Question 31

Do hermaphrodites self fertilize?

Answer 31

No-they will exchange sperm and use the other's to fertilize their own eggs

Question 32

How does oogenesis begin?

Answer 32

With oogonia, a type of diploid cells

Question 33

What do the oogonia develop into? When?

Answer 33

Cells called primary oocytes. prenatally

Question 34

What stage are the primary oocytes in at time of birth?

Answer 34

Prophase of meiosis I. They then enter a resting phase.

Question 35

What happens after a female goes through puberty to the primary oocytes?

Answer 35

It completes Meiosis I once a month

Question 36

What does Meiosis I of the primary oocyte form every month?

Answer 36

Two cells, a polar body and secondary oocyte.

Question 37

What is the polar body that resulted from Meiosis I of the primary oocyte?

Answer 37

a small, nonfunctional cell

Question 38

Which of the two resulting cells of female Meiosis I (the polar body and secondary oocyte) is larger? What did this result in?

Answer 38

The secondary oocyte. It therefore receives most of the cytoplasm.

Question 39

What occurs at fertilization?

Answer 39

Meiosis II

Question 40

What happens when Meiosis II occurs to the secondary oocyte?

Answer 40

The secondary oocyte divides into an ootid and a polar body.

Question 41

What may happen to the polar body that resulted from Meiosis II of the secondary oocyte?

Answer 41

It may split into 2 polar bodies

Question 42

What happens to the female polar bodies?

Answer 42

They die

Question 43

What happens to the ootid?

Answer 43

It grows into a mature egg

Question 44

What is spermatogenesis?

Answer 44

process of forming sperm that occurs in the testes

Question 45

What does spermatogenesis begin with?

Answer 45

Spermatogonia (diploid cells that a man is born with)

Question 46

What happens to the spermatogonia throughout the life of a male?

Answer 46

They divide by mitosis to form more of them

Question 47

What happens to some spermatogonia?

Answer 47

They enlarge, become primary spermatocytes

Question 48

What happens to the primary spermatocytes?

Answer 48

They go through meiosis I, form 2 cells of equal sizes called secondary spermatocytes?

Question 49

What happens to each secondary spermatocyte?

Answer 49

It goes through meiosis II to form four equal sized cells called spermatids

Question 50

What happens to spermatids?

Answer 50

They grow tails and become sperm cells

Question 51

What's the difference in chromosome number between mitosis and meiosis?

Answer 51

Diploid for mitosis, haploid meiosis

Question 52

What's the difference in chromosome distribution between mitosis and meiosis?

Answer 52

mitosis-daughter cells have same number and type as parent cells. meiosis-daughter cells have 1 chromosome from each homologous pair and each chromosome is different due to crossing over

Question 53

What's the difference in function of cells produced between mitosis and meiosis?

Answer 53

mitosis-additional body cells for growth, and for unicellular or simple multicellular organisms, it's a form of asexual reproduction. meiosis produces gametes.

Question 54

Homologous chromosomes

Answer 54

one of a pair of chromosomes that match up at meiosis