Cytogenetics - def'n n stuff

Question 1

Define cytogenetics

Answer 1

study of chromosome number, structure and function

Question 2

Describe the structural chromosomal aberration deletion.

Answer 2

• occurs when part of chromosome breaks and a piece is lost
• results in partial monosomy
• can be terminal or interstitial deletion

Question 3

Provide example of disease caused by:

a) Terminal deletion
b) Interstitial deletion

Answer 3

a) Terminal = cri du chat (5p)

b) Interstit = williams syndrome

Question 4

What is an isochromosome?

Answer 4

A chromosome that is not split at the right place, instead of splitting down midline of centromere, it splits horizontally, splitting the chromosome into a pair with the p (small) arms, and a pair with the q arms

Question 5

How does a ring chromosome form?

Answer 5

The telomeres break off of the chromosome, and the remaining fragments on the 2 ends join together and fuse to create a ring