Unit 10.4

Question 1

Definition of nondisjunction

Answer 1

This is when chromosomes don’t seperate properly druing meiosis

Question 2

Definition of Trisomy

Answer 2

Diploid cells that have one chromosome type (2n+1)

Question 3

Definition of Monosomy

Answer 3

Diploid cells have only one copy of a chromosome (2n-1)

Question 4

What are autosomes?

Answer 4

This is any chromosome that is not a sex chromosome

Question 5

What are sex chromosomes?

Answer 5

Genes that determine the sex of the organism.

Question 6

What is a Barr Body?

Answer 6

Barr bodies make all the un-needed X chromosomes inactive

Question 7

What is deletion?

Answer 7

This is when genes are missing which for the zygote means it might not make enough functional protein.

Question 8

What is duplication?

Answer 8

This is when there are extra genes, which means for the zygote they might make too much of a protein

Question 9

What is inversion?

Answer 9

This is most likely no switch in genes and the zygote might have trouble pairing chromosomes for meiosis or have issues with fertility.

Question 10

What is translocation?

Answer 10

Some genes may be missing some, others may have extra. For the zygote this means that it could make too much or too little of a functional protein or it could be normal.

Question 11

How does nondisjunction lead to the incorrect amount of chromosomes?

Answer 11

They don’t divide correctly, so one cell has more chromosomes then it needs and the other is left with none

Question 12

What determines human biological sex at birth?

Answer 12

Whether or not the Y chromosome is present

Question 13

What type of reproductive system and how many Barr bodies would a XXX chromosome have?

Answer 13

Female, 2 Barr bodies

Question 14

What type of reproductive system and how many Barr bodies would a XXY chromosome have?

Answer 14

Male, 1 Barr body