Genetic problems

Genetic problems: Must do 3 to 7

You can choose to do 1, and 2 or just 8 total number of genetic problems should be 6

1. Create a Punnett Square for a heterozygous individual (a+/a) crossed with a heterozygous individual (a+/a). In this case, the mutation is recessive.

Determine the genotypic ratio and phenotypic ratio.

For phenotypic ratio do not refer to specific a+ or a phenotype but instead refer to them as dominant or recessive.

2. Create a Punnett Square for a heterozygous individual crossed with a heterozygous individual.

Make the mutation dominant. Notice that the phenotypic ratio for dominant/recessive is identical to Q1 (3/4 Dominant, 1/4 recessive) except you now have to realize your mutation is Dominant, and wild-type is recessive.

3. You and your spouse have no children. You stand to inherit a sizeable fortune from your crazy Uncle Irving if you can produce three daughters in your family of three children. What is the probability of doing just that?

4. If you could convince Uncle Irving that simply having three children all of the same sex would do, then what would be the probability of your receiving the inheritance?

5. In quest of the family stipulated in #4 above, you produce a boy as your first child. Now, what is the probability of inheriting the fortune?

6. Why are the answers to #4 and #5 the same?

7. Finally, you have convinced Uncle Irving that you will agree to try for at least three girls out of four children. How likely are you to become wealthy given those conditions?

8. Research has shown that a particular eye defect is represented in a family pedigree as follows: A B C

a. By this data, which of the following mechanisms of inheritance are POSSIBLE? Autosomal dominant, autosomal recessive, sex-linked dominant, sex-linked recessive, Y-linked.

b. What is the most PROBABLE mechanism of inheritance?

c. What is the genotype of female A?

d. What is the genotype of male B?

e. What is the probability that a child from marriage C will show this eye defect?