II term questions and problems

Question 1

a woman has a sister with a rare AR disorder.

if she has a child with her nephew (son of unaffected brother) what is the chance the pregnancy will be affected?

Answer 1

• draw the pedigree
• formula (P = probability)
  
  • (P mom 2b carrier)(P mom passes”a”)(P father carrier)(P father passes”a”)
  • (2/3)(1/2)(1/3)(1/2) = 1/18

Answer 2

prob of a carrier to pass the disease is 1/2 (in AR)

see result in figure

Question 3

Answer 3

Question 4

Answer 4

the chances decreases from 2/3 to 1/2 because its an unknown mutation

Question 5

what is chromosomal tracking?

Answer 5

its when you mark the repeats in the chromosome.on the graph the numbers are the numbers of repeats

Question 6

Answer 6

Question 7

Answer 7

half

Question 8

Answer 8

answer is B

Question 9

Answer 9

prob man to be a carrier is 2/3

prob of passing “a” is 1/2

the mother (no fam hx) of being a carrier is 1/25

mother passing the “a” 1/2