Tutorial Week 3

Question 1

What is a translocation

Answer 1

When a chromsome breaks and there is a reararngement of parts between nonhomolgous chromsones

Question 2

What can balanced translocation result in

Answer 2

Duplication and deleteions during reproduction

Question 3

Are balanced translocation always inherited

Answer 3

NO

Question 4

When do de novo balanced translocations occur

Answer 4

During gamete formation

Question 5

When can translocations occur

Answer 5

Errors in replication/reapir
Prophase of meiosis 1
Metaphaose of meiosis 2

Question 6

What chromsones are acrocentric in humans

Answer 6

13,14,15,21,22

Question 7

What is a robertosonina translocation

Answer 7

Form of chromsomal rearrangment where the acrocentric chromsomes break at their centromere and the long q arms fuse to forma. single large chromsones with one centermoe and the very small non essential genes are usually lost

Question 8

How would you express a robertosnina translocation

Answer 8

45,XX,der(14;21)(q10;q10) the breakage is going to be at the centromere and der is for derivative

Question 9

What are the possibilited of the roberstonian translocation

Answer 9

You would have either a monosomy where you only have the one chrosmome
Trisomoy where you have three of the same
Or unaffecter or just the carrier so 1/3 of your kids will be affected

Question 10

What is FISH used for

Answer 10

To visualize chromsome abnormalities

Question 11

How does FISH work

Answer 11

Probe is labelled with a fluorophore so that it can be seen under a microscope
Denaturation followed by hybridzation will show where the probe had bound genome DNA
Usuallt in a hyoptonic solution during metaphase when they are condensed

Question 12

What can FISH be helpful for

Answer 12

Easily identifying aneuplodies and large structural changes