Human Biology: Test 5 (Chapters 18, 19, 20)

Question 1

Describe the main parts of the cell cycle.

Answer 1

G1 stage occurs before DNA synthesis
S stage includes DNA synthesis
G2 stage occurs after DNA synthesis

Question 2

What is the importance of mitosis?

Answer 2

Cloning is the importance of mitosis. It has no differences.

Or

The new daughter cells has the same number of chromosomes as the parent cell.

Question 3

What is the significance of meiosis?

Answer 3

To make sex cells which have half of the chromosomes as the parents.

Question 4

What is nondisjunction?

Answer 4

When either homologous chromosomes or sister chromatids fail to separate.

Question 5

List three syndromes caused by abnormal chromosomes number.

Answer 5

Jacobs syndrome
Turner syndrome
Klinefelter syndrome

Question 6

What does it mean to be a carrier of a gene?

Answer 6

A carrier is a person who appears to carry one trait but carry a different trait.

Question 7

How can variation in a trait help determine the type of inheritance?

Answer 7

The more variation, the more likely its a polygenic trait.

Question 8

Explain why it is the father that determines the sex of the child.

Answer 8

Since the father is xy, they can get one or the other.

Question 9

Explain why an X-linked trait affects men more than women.

Answer 9

Because women have 2 X’s and men only have 1.

Question 10

What is the history behind HeLa Cells?

Answer 10

HeLa cells are Descendent’s of tumor cells from a woman named Henrietta Lacks. They are a line of human cancer cells that can grow in the lab. Although lacks died at 31, her cells continue to live and divide in labs around the world.

Question 11

Both parents have unattached earlobes yet some of their children have attached earlobes. Explain.

Answer 11

Parents carried the attached gene.