Chapter 2: Mitosis and Meiosis

Question 1

Are somatic cells haploid or diploid?

Answer 1

Diploid. They all contain the same number of chromosomes as the parent cell.

Question 2

What does “homologous chromosomes” mean?

Answer 2

The pair of chromosomes in somatic cells. Each member of the pair is a homologous chromosome.

Question 3

This number is one half of the diploid number, and these chromosomes as a set make up the genome.

Answer 3

Haploid number.

Question 4

During this phase in the cell cycle, DNA is being synthesized in preparation for mitosis.

Answer 4

S phase

Question 5

This phase of the cell cycle comes before S phase. No DNA synthesis is occurring during this phase.

Answer 5

G1 phase

Question 6

This phase of the cell cycle comes after S phase right before mitosis. No DNA synthesis is occurring during this phase.

Answer 6

G2 phase

Question 7

During this phase of the cell cycle, a cell decides to become non-dividing and stops going through the cell cycle.

Answer 7

G0 phase

Question 8

During this stage of mitosis, the DNA condenses into chromosomes and the nuclear membrane starts to break down.

Answer 8

Prophase

Question 9

During this stage of mitosis, the chromosomes are pulled by kinetochore microtubules to the center of the metaphase plate, where their centromeres are lined up.

Answer 9

Metaphase

Question 10

During this stage of mitosis, the centromeres let go and the sister chromatids are pulled to opposite sides of the cell by microtubules.

Answer 10

Anaphase

Question 11

During this stage of mitosis, each of the two sister chromatids is present in the cell until the cell splits down the middle (cytokinesis).

Answer 11

Telophase

Question 12

In meiosis, genetic material passed on to daughter cells (gametes) is cut in half because you end up with one _______ set of chromosomes.

Answer 12

Haploid

Question 13

During this stage of meiosis, DNA condenses into chromosomes and the nuclear envelope breaks down. Recombination is occurring.

Answer 13

Prophase I

Question 14

During this stage of meiosis, the homologous chromosomes line up in at the center of the cell. Recombination is occurring.

Answer 14

Metaphase I

Question 15

During this stage of meiosis, the chromosomes move to opposite sides of the cell. Each daughter cell has 23 chromosomes.

Answer 15

Anaphase I

Question 16

During this stage of meiosis, the parent cells split into two daughter cells, each with the 23 chromosomes.

Answer 16

Telophase I

Question 17

During this stage of meiosis, the spindles begin to form in the daughter cells.

Answer 17

Prophase II

Question 18

During this phase of meiosis, the chromosomes line up along the middle of the cell.

Answer 18

Metaphase II

Question 19

During this phase of meiosis, the chromosomes are pulled apart into their sister chromatids to opposite sides of the cell.

Answer 19

Anaphase II

Question 20

During this phase of meiosis, each of the two daughter cells divides again.

Answer 20

Telophase II

Question 21

Meiosis results in ________ (haploid/diploid) gametes.

Answer 21

4, haploid

Question 22

In males, gamete formation results in ___ sperms.

Answer 22

four

Question 23

In females, gamete formation results in ___ egg(s).

Answer 23

one

Question 24

How do you end up with one egg for females?

Answer 24

The primary oocyte divides. One daughter cell is the secondary oocyte and gets more cytoplasm. The other is the first polar body. Then the secondary oocyte divides, resulting in the ootid and the second polar body, and the ootid becomes the ovum that’s released during ovulation.

Question 25

When does DNA replication occur for the eggs –before ovulation or when it’s time to ovulate?

Answer 25

Before, during embryonic development. The primary oocyte starts on meiosis I, but arrests after prophase (replication of DNA is completed here). Years later, when it’s time to start ovulating, one primary oocyte per ovulation gets to continue with meiosis and go to completion, making an ovum and releasing the egg.