Chapter 7.4 Meiosis

Question 1

What is a karyotype?

Answer 1

It is a diagram showing homologous chromosomes.

Question 2

What are homologous chromosomes?

Answer 2

Chromosomes that carry the same genes, one coming from the female parent, one comong from the male parent.

Question 3

How many chromosomes do humans have in regular body cells?

Answer 3

46

Question 4

How many chromosomes do humans have in sex cells?

Answer 4

23

Question 5

What is another name for a gamete or germ cell?

Answer 5

Sex cell

Question 6

What is a somatic cell?

Answer 6

A body cell

Question 7

What is a complete set of chromosomes called?

Answer 7

Diploid

Question 8

What is half a set of chromosomes called?

Answer 8

Haploid

Question 9

What is the notation for a diploid set of chromosomes?

Answer 9

2N

Question 10

What is the notation for a haploid set of chromosomes?

Answer 10

N

Question 11

What is meiosis?

Answer 11

The process by which the number of chromosomes is reduced by half as sex cells form.

Question 12

Where does meiosis occur?

Answer 12

In the sex organs -
Testes in males
Ovaries in females

Question 13

Where does mitosis occur.

Answer 13

In body cells (somatic cells)

Question 14

In which stage of meiosis (I or II) do chromosomes double?

Answer 14

Meiosis I

Question 15

What is crossover and homologous recombination?

Answer 15

During prophase 1 of meiosis, as homologous chromosomes pair up and form tetrads, they exchange portions of their chromatids

• tangled up = cross-over
• trade sections of DNA (from the same location on chromosome) = recombination

Question 16

What happens to the pairs of homologous chromosomes during anaphase 1 of meiosis?

Answer 16

Tetrads separate
Homologous chromosomes move to opposite side of cell
Sister chromatids remain attached

Question 17

How many and what type of cells are formed at the end of meiosis I?

Answer 17

2 diploid cells with the same number of chromosomes as the parent cell

Question 18

What happens to chromosomes during prophase II of meiosos?

Answer 18

Chromosomes thicken but DO NOT double

Question 19

What happens during to the chromasomes during anaphase II?

Answer 19

Sister chromatids of each chromosome move to opposite ends toward the centrioles

Question 20

How many and what type of cells are formed at the end of meiosis II?

Answer 20

4 unique (different) and haploid cells with half the chromosomes of the starting cell