Packet 2 (genetics)

Question 1

Draw out a Punnett Square where the mom is a carrier (affected) of Hemophilia A, and the dad is normal (unaffected).

1. ) What are the chances their daughters will be carriers?
2. ) What are the chances their sons will have the disease?

Answer 1

Daughters: 50% carrier

Sons: 50% disease

X with circle represents defective gene

Question 2

Draw out a Punnett Square for autosomal recessive disorders where both of the parents are carriers of the disease.

1. ) What are the chances that this couple will have a child with the disease?
2. ) What are the chances that this couple will have a child that is normal?
3. ) What are the chances that their child will be a carrier of the disease?

Answer 2

25% chance of having disease

25% chance of being normal

50% chance of being carriers

Question 3

Draw out a Punnett Square for autosomal recessive disorders where one of the parents is affected and the other parent is a carrier.

1. ) What are the chances that this couple will have a child with the disease?
2. ) What are the chances that their child will be a carrier of the disease?

Answer 3

50% chance of having disease

50% chance of being carriers

Question 4

Draw out a Punnett Square for X-linked disorders where the mom is normal (unaffected) and the dad is affected.

1. ) What are the chances their daughters will be carriers?
2. ) What are the chances their sons will have the disease?

Answer 4

Daughters: All carriers

Sons: All normal

X with circle represents defective gene

Question 5

Draw out a Punnett Square for autosomal recessive disorders where both of the parents are affected by the disease.

1.) What are the chances that this couple will have a child with the disease?

Answer 5

All have disease (100% chance)

Question 6

Draw out a Punnett Square for X-linked disorders where the mom is a carrier (infected), and the dad is normal (unaffected).

1. ) What are the chances their daughters will be carriers?
2. ) What are the chances their sons will have the disease?

Answer 6

Daughters: 50% carrier

Sons: 50% disease

X with circle represents defective gene

Question 7

Draw out a Punnett Square for an autosomal dominant disorder where one parent is affected, and one parent is unaffected.

1. ) What are the chances that this couple will have a child with the disease?
2. ) Will there be any carriers?

Answer 7

50% chance of having disease

No carriers

Autosomal Dominant Disorder ⇒ Aa

A - represents defective gene (trait is dominant)

Question 8

Draw out a Punnett Square where both of the parents are carriers of Sickle cell anemia.

1. ) What are the chances that this couple will have a child with the disease?
2. ) What are the chances that this couple will have a child that is normal?
3. ) What are the chances that their child will be a carrier of the disease?

Answer 8

25% chance of having disease

25% chance of being normal

50% chance of being carriers

Question 9

Draw out a Punnett Square for autosomal recessive disorders where one of the parents is affected and the other parent is normal.

1.) What are the chances that their child will be a carrier of the disease?

Answer 9

All carriers (100% chance)

Question 10

Draw out a Punnett Square where one parent is affected by Marfan Syndrome, and one parent is unaffected.

1. ) What are the chances that this couple will have a child with the disease?
2. ) Will there be any carriers?

Answer 10

50% chance of having disease

No carriers

Autosomal Dominant Disorder ⇒ Aa

A - represents defective gene (trait is dominant)