13

Question 1

What is meiosis? How is it different from mitosis?

Answer 1

1. Cell division of sex organs
2. Produces gambetes

Question 2

Testes produce what?
Ovaries produce what?

Answer 2

Sperm, eggs

Question 3

What are the 5 properties of mitosis that make it different from meiosis?

Answer 3

1. Results in 2 identical daughter cell
2. Only 2 division
3. No crossing over
4. Happens in somatic cells
5. No genetic diversity other than mutations

Question 4

What are the 5 properties of meiosis that make it different from mitosis?

Answer 4

1. Results in 4, not 2, DIFFERENT, not identical, daughter cells
2. 2 separate cell divisions (Meiosis 1 and Meiosis 2)
3. Synapsis results in crossing over
4. Independent assortment
5. Law of segregation

Question 5

What is synapsis? What does it result in?

Answer 5

1. The pairing of homologous chromosomes
2. Results in crossing over

Question 6

When does independent assortment occur?

Answer 6

Metaphase 1

Question 7

When does the law of segregation occur?

Answer 7

Anaphase 1 and 2

Question 8

What are the properties of Diploid cells?

Answer 8

1. 2 complete sets of chromosomes
2. All cells are diploid other than sex cells

Question 9

What does 2n mean in 2n=46?

Answer 9

1. Diploid
2. The number of SETS of chromosomes is 2n
3. 46 is the number of chromosomes that it contains

Meaning, if 2n is the number of diploid, n would be the number of haploid. So, if 2n=46, n=23.

Question 10

How many homologous pairs of chromosomes to humans have?

Answer 10

23

Question 11

How many chromosomes do humans have in total?

Answer 11

46

Question 12

How many chromosomes do each of our gametes have?

Answer 12

23

Question 13

Which cells are haploid?

Answer 13

Sex cells

Question 14

Which cells are diploid?

Answer 14

All cells except sex cells

Question 15

what happens in meiosis 1?

Answer 15

Homologous chromosomes are separated into daughter cells

Question 16

What are the steps of meiosis 1?

Answer 16

1. Prophase 1
2. Metaphase 1
3. Anaphase 1
4. Telophase 1
5. Cytokinesis

Question 17

What happens in prophase 1?

Answer 17

1. Synapsis
2. Crossing over

Question 18

What is it called when homologous chromosomes pair up?

Answer 18

A tetrad

Question 19

What happens when a cell forms a tetrad?

Answer 19

It becomes diploid

Question 20

What happens during crossing over?

Answer 20

Parts of 1 homologous chromosome are swapped with the other chromosome (think of swapping parts on a Lego set from one set to another)

Question 21

What happens at metaphase 1? There is 1 major event

Answer 21

Homologous chromosomes line up at the metabolic plate independently. This is independent assortment

Question 22

What is independent assortment?

Answer 22

Homologous chromosomes lining up at the metabolic plate independently

Question 23

When does Independent assortment occur?

Answer 23

Metaphase 1

Question 24

What happens at anaphase 1?

Answer 24

Homologous chromosomes split and go to separate daughter cells. This is the law of segregation.

Question 25

What is the law of segregation?

Answer 25

Homologous chromosomes split and go to separate daughter cells.

Question 26

What happens at telophase 1?

Answer 26

Cytoplasm splits and two separate cells result with a COMPLETE chromosomes, each having 2 sister chromatids

Question 27

What happens at prophase 2?

Answer 27

Spindle fibers reform

Question 28

What happens at metaphase 2?

Answer 28

Chromosome line up at the metabolic plate.

Question 29

Are the chromosomes identical at metaphase 2? Why it why not?

Answer 29

No, because of Crossing Over at prophase 1

Question 30

What happens at anaphase 2?

Answer 30

The sister chromatids separate from each other. the law of segregation.

Question 31

What happens at telophase 2? What state are the cells in now?

Answer 31

1. 4 daughter cells are created 2. The cells are now haploid (n) because they only have 1 sister chromatid per chromosome.

Question 32

Does crossing over occur in mitosis?

Answer 32

NO!!

Question 33

What are the 3 sources of genetic variation?

Answer 33

1. Independent assortment 2. Crossing over 3. Random fertilization

Question 34

What is the equation for possible number of combinations during independent assortment?

Answer 34

2^n = the number of possibilities. N would be the haploid #.

Question 35

If n = 25, how many possible combinations are there?

Answer 35

Almost 34,000,000

Question 36

What is it called when homologous chromosomes swap segments of DNA? (Remember the legos)

Answer 36

Crossing over

Question 37

What is random fertilization?

Answer 37

Any egg cell can match with any sperm cell