Chapter 2 Cell Division

Question 1

Interphase includes the following stages:

Answer 1

G1, S, G2

Question 2

You are a scientist attempting to study cellular division. You want to know what stage of cellular reproduction you are at. You look at the cells under a light microscope and notice no chromosomes. What stage(s) are you NOT in, and why?

Answer 2

Since the chromosomes are not visible, that means the genetic material is in a form known as chromatin; the DNA is NOT condensed so that it can be effectively replicated and DNA POL can get to the DNA.

Question 3

Why would it be effective for DNA to be condensed during mitosis?

Answer 3

So that DNA is neatly packed and the daughter cells do not lose any information.

Question 4

What are the 4 stages of the Cell Cycle? And what is the stage at which most cells reside (not included in the 4)?

Answer 4

1) G1
2) S
3) G2
4) M

G0 Cellular Arrest

Question 5

During the G1 stage, what is the cell doing to prepare for synthesis of DNA?

Answer 5

The cell is preparing for replication of the genome, so it needs both energy and space. To do this,

Question 6

During the end of Synthesis stage, how many chromatids are present? How many chromosomes?

Answer 6

There are 92 chromatids, but 46 chromosomes. Each chromosome has a sister chromatid.

Question 7

True or False: After the synthesis stage, one chromosome contains two identical copies of a chromatid

Answer 7

TRUE; Before synthesis, a chromosome is classified as how many distinct DS DNA’s are from one respective parent. After synthesis, each chromosome from the father and mother is replicated into a sister chromatid.

Question 8

During the G2 stage, what occurs?

Answer 8

The cell is ensuring DNA replicated correctly and growing to accommodate for the new genetic information to prep to be split.

Question 9

Mitosis

Answer 9

Mitosis is the splitting & separation of the nucleus and is divided into 4 stages.

Question 10

4 stages of Mitosis

Answer 10

Prophase, Metaphase, Anaphase, Telophase

Question 11

What occurs during Prophase?

Answer 11

During prophase:

• The chromatin condenses into its respective 46 pairs of 92 sister chromatids.
• The centrosome, containing two centriole pairs, migrate to opposite poles of the cell
• Some of the microtubules formed from the centriole form asters with the membrane to anchor it
• The fiber microtubules connect to the kinetochores

Question 12

Metaphase

Answer 12

The centriole pairs reside at opposite sides of the cell and the spindle apparatus aligns the chromosomes along the equatorial plate

Question 13

Anaphase

Answer 13

The centromeres split (and therefore the sister chromatids). So there are now 92 chromosomes and 92 chromatids.

Question 14

Telophase

Answer 14

During Telophase, the distinct nuclear membrane appears around the 46 chromosomes. The chromosomes come together and form 23 pairs.

Question 15

Meiosis

Answer 15

Meiosis is distinct and separate from Mitosis. Meiosis only occurs in sex cells whereas Mitosis occurs during actively dividing (replicating) autosomal cells.