Genetics Lecture 10 - Cytogenetics 2

Question 1

Do aquired genetic changes (such as in cancer) affect phenotype?

Answer 1

No

Question 2

In which cells do aquired changes reflect an altered karyotype?

Answer 2

In the cancer cells only (eg. bone marrow only).

Question 3

What are metacentric chromosomes?

Answer 3

Centromere divides the chromosome in half

Question 4

What are submetacentric chromosomes?

Answer 4

q and p arms

Question 5

What are acrocentric chromosomes?

Answer 5

Nub p arm

Question 6

What is a Robertsonian translocation?

Answer 6

Loss of the p arm of an acrosentric chromosome and fusion with another acrocentric chromosome. The centromeres of the chromosomes split and they fuse.

Question 7

What does (q10) represent?

Answer 7

A Robertsonian translocation.

Question 8

What does this mean: 45, XY, der(15;22) (q10;q10)?

Answer 8

Male with Robertsonian translocation between chromosomes 15 and 22.

Question 9

Do people with Robertsonian translocations have phenotypic effects?

Answer 9

No

Question 10

When people with Robertsonian translocations try to have children, can that be problematic?

Answer 10

Yes, in meiosis many cells will end up with too many chromosomal info or with no chromosomes at all.

Question 11

If a translocation occurs between a X chromosome and an autosomal chromosome, which chromosome will be inactivated?

Answer 11

The normal x (to save the autosomal genes)

Question 12

In isochromosome q of the X chromosome, which chromosome will be inactivated?

Answer 12

The abnormal isochromosome X

Question 13

Can you have changes in copy number of virtually any chromosome in acquired changes?

Answer 13

Yes

Question 14

Which are the acrocentric chromosomes?

Answer 14

13, 14, 15, 21, 22