7.5 study guide

Question 1

What’s non-dis junction?

Answer 1

chromosomes don’t separate properly during meiosis.

Question 2

When can non-disjunction happen in Meiosis 1?

Answer 2

homologous chromosomes fail seperate

Question 3

When can non-disjuction happen in Meiosis 2?

Answer 3

Sister chromatids fail to seperate

Question 4

How many of each chromosome type should a normal gamete have?

Answer 4

1

Question 5

What about a normal zygote?

Answer 5

2

Question 6

Why are humans more tolerant of extra sex chromosomes then autosomes?

Answer 6

We have more x-chromosomes to start with.

Question 7

What determines whether a human’s biological sex at birth will be male or female?

Answer 7

The sex chromosomes that a male sperm carries.

Question 8

What happens during X-chromosome inactivation?

Answer 8

An x chromosome is compacted to make a small, dense structure called a Barr body.

Question 9

What’s an Autosome?

Answer 9

One of the numbered chromosomes, as opposed to the sex chromosomes.

Question 10

What are sex chromosomes?

Answer 10

A type of chromosome involved in sex determination.