Lecture 6

Question 1

What does cytogenetics allow?

Answer 1

Allows researchers to profile amplifications, deletions, rearrangements, point mutations, copy number changes

Question 2

What does the nucleus contain when the cell is not dividing? and what happens when it begins to divide?

Answer 2

Chromatin condenses to chromosomes

Question 3

What is FISH?

Answer 3

Fluorescent In Situ Hybridisation, the probes will be specific to different regions on the chromosome. Can allow you to identify all the chromosomes.

Question 4

What is a floppy baby with a single crease across the palm representative of?

Answer 4

Downs Syndrome (Trisomy 21)

Question 5

What is Ploidy and Aneuploidy?

Answer 5

Ploidy - Wrong number of complete chromosome sets

Aneuploidy - Specific additional or missing chromosomes

Question 6

What happens in females regarding the X chromosome?

Answer 6

One X silences and only 15% of its genes are functionally expressd.

Question 7

What happens when individuals are 45 X, 47 XXX, 47 XYY and 47 XXY

Answer 7

45 X - females infertile, broad chest
47 XXX - females mostly undiagnosed
47 XYY - males, tall many undiagnosed
47 XXY - males, infertile, lower IQ, pubertal failure

Question 8

What are two powerful tools to detect deletions?

Answer 8

Comparative Genomic Hybridisation (CGH) and Single Nucleotide Polymorphisms (SNP)