Chromosome Abberations

Question 1

What is a chromosome aberration?

Answer 1

• Deletion
• Duplication
• inversions
• non-reciprocal translocations
• reciprocal translocations

Question 2

Explain deletions -chromosome deletions

Answer 2

When a chromosome breaks in one or more places, and a piece is lost,it is now a deletion chromosome

Question 3

What are the types of deletions?

Answer 3

Terminal deletions- the deletion occurs near one end of the chromosome

Intercalary deletion- deletion in the interior of the chromosome

Question 4

How can intercalary deletions be detect?

Answer 4

Portion of the chromosome with the centromere will be maintained as the cell divides

The rest of chromosome may be lost following meiosis or mitosis.

Intercalary deletions can be detected when pairing of homologs in meiosis show a deficiency loop where a piece is missing

Question 5

What is cri-du-caht syndrome ?

Answer 5

Characterized by:

1. Retardadtion
2. Weak, high-pitched, catlike cry

Question 6

What causes Cri-du-can’t syndrome?

Answer 6

Chromosome 5 terminal deletion results in gamete carrying a deletion

Fertilization of the gamete forms a zygote that is heterozygous for the deletion