Mitosis and Meiosis

Question 1

What are the differences in the RESULT of meiosis and mitosis?

Answer 1

For meiosis, the results are 4 haploid daughter cells that are non-identical to the parent or one another. For mitosis it’s 2 diploid daughter cells that are indentical to the parent and one another.

Question 2

What happens in interphase

Answer 2

Cell growth, DNA replicated, organelles grow.

Question 3

What’s unique in prophase 1 for meiosis? Explain

Answer 3

Crossing over happens. This happens when homologous pairs of chromosomes (one from father, one from mother) line up and parts are exchanged.

Question 4

What happens during prophase for mitosis?

Answer 4

Chromatin condenses into chromosomes, nuclear membrane breaks apart

Question 5

What are haploid and diploid cells. What’s the difference?

Answer 5

Haploid: one set of chromosomes, “n” chromosomes, gametes.
Diploid: 2 sets of chromosomes, “2n”, somatic.

Question 6

What phase is it when the chromosomes are pulled apart?

Answer 6

Anaphase.

Question 7

What prevents the cell from getting smaller and smaller between each division?

Answer 7

Cells grow to maintain their size between each division.

Question 8

Why does the cell need to duplicate it’s DNA?

Answer 8

To make sure each daughter cell receives the complete copy of the parent’s DNA.

Question 9

What happens in cytokinesis?

Answer 9

The sides of the cell pinch inwards, dividing the cell into 2.

Question 10

What reappears in telophase? Why does it go away through the first 3 steps of mitosis?

Answer 10

The nuclear membrane. So, the chromatids can be pulled to the sides of the cell.

Question 11

What’s the purpose of Mitosis?

Answer 11

Growth: increase # of cells
Repair wounds: To repair parts of the body that have been acidently damaged. Ex. injuries

Question 12

In meiosis what’s the difference between anaphase 1 and 2?

Answer 12

In anaphase 1, homologous chromosomes separate when pulled apart to the opposite poles of the cell, but sister chromatids stay together. In anaphase 2, sister chromatids are pulled apart.

Question 13

Why don’t red blood cells perform mitosis?

Answer 13

Because they don’t have a nucleus. They don’t have a nucleus because they need room to transport oxygen.

Question 14

What’s the only way to make gametes?

Answer 14

Meiosis

Question 15

What happens during anaphase for mitosis?

Answer 15

sister chromatids are pulled apart to the opposite poles of the cells by spindles.

Question 16

How many chromatids are there before interphase, after interphase and after mitosis?

Answer 16

46, 92, 46.

Question 17

How many chromosomes are there before interphase, after interphase, after meiosis 1 and after meiosis 2?

Answer 17

46, 46, 23, 23

Question 18

What is the relationship between chromatin and chromosomes?

Answer 18

Chromatin condenses to form chromosomes. They’re made up of the same material: DNA.

Question 19

During what phase does the spindle form?

Answer 19

Prophase.

Question 20

During metaphase, the chromosomes line up along the…

Answer 20

equator

Question 21

What are homologous chromosomes?

Answer 21

Homologous chromosomes are 2 chromosomes that are similar in length and gene order. One comes from the mother and the other comes from the mother

Question 22

What are sister chromatids?

Answer 22

2 chromatids joined at a centromere that are identical to one another

Question 23

What is uncoiled DNA called?

Answer 23

Chromatin

Question 24

what is # does “n” refer to for humans?

Answer 24

23

Question 25

What does crossing over benefit?

Answer 25

genetic diversity because parts of the father’s and mother’s chromosome are exchanged.

Question 26

Why don’t we do crossing over in mitosis?

Answer 26

It’s because the goal of mitosis is to make identical cells, not to make different cells. (Crossing over results in non-identical cells)

Question 27

What happens during metaphase?

Answer 27

Chromosomes line up at the equator of the cell and each centromere of the chromosome attaches itself to a spindle fibre.

Question 28

Why doesn’t the DNA replicated before prophase 2?

Answer 28

because it would create diploid cells instead of haploid cells.

Question 29

The cytoplasm splits into 2 identical daughter cells during this process:

Answer 29

Telophase

Question 30

What are amitotic cells? Examples?

Answer 30

Cells that can’t reproduce through mitosis. RBC, nerve cells in spinal cord.