Genetic Inheritance Patterns

A man with an autosomal dominant disorder has children with a woman who is healthy. The probability that their first child will inherit the disorder if the disorder allele is represented as "A" and the normal allele as "a" is (a)   .

• 25%

• 50%

• 75%

• 100%

Answer explanation

Answer Explanation highlighting the correct choice of 50%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

In an autosomal recessive inheritance pattern, two parents are carriers of a recessive allele for a genetic disorder. The chance that their child will be affected by the disorder is _____​

• 25%

• 75%

• 10%

• 50%

Answer explanation

In an autosomal recessive inheritance pattern, when both parents are carriers, there is a 25% chance that their child will be affected by the disorder.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

A woman with an X-linked dominant disorder has children with a man who does not have the disorder. The probability that their son will inherit the disorder is (a)   .

• 0%

• 25%

• 50%

• 100%

Answer explanation

The son has a 50% chance of inheriting the X-linked dominant disorder from the mother, as he will receive either her affected X chromosome or the father's Y chromosome.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

In X-linked recessive inheritance, a healthy woman (carrier) and a healthy man have a child. What is the probability that their daughter will be a carrier of the X-linked recessive trait?

• 0%

• 25%

• 50%

• 100%

Answer explanation

The daughter has a 50% chance of inheriting the X-linked recessive trait from her carrier mother, making her a carrier as well.

Tags

NGSS.HS-LS3-1

If a man with an X-linked recessive disorder has children with a woman who does not carry the disorder, the probability that their daughters will be carriers is (a)   .

• 0%

• 25%

• 50%

• 100%

Answer explanation

Daughters of a man with an X-linked recessive disorder and a woman without the disorder will all be carriers, resulting in a 100% probability of their daughters being carriers.

Tags

NGSS.HS-LS3-1

A child inherits a mitochondrial disorder. Which parent is most likely to have passed on this disorder?

• The father

• The mother

• Both parents equally

• It is impossible to determine

Answer explanation

The mother is most likely to have passed on the mitochondrial disorder because mitochondria are inherited exclusively from the mother.

Tags

NGSS.HS-LS3-1

In a family where both parents are carriers of an autosomal recessive disease, they have three children. The probability that at least one of their children will be affected by the disease is (a)   .

• 25%

• 50%

• 57.81%

• 75%

Answer explanation

The probability of at least one child being affected by an autosomal recessive disease when both parents are carriers is calculated using the complement rule: 1 - (probability of no children being affected) = 1 - (0.75)^3 = 0.5781 or 57.81%

Tags

NGSS.HS-LS3-3

A man with an X-linked recessive disorder and a woman who is a carrier for the same disorder have a child. What is the probability that their son will have the disorder?

• 25%

• 50%

• 75%

• 100%

Answer explanation

The son has a 50% chance of inheriting the X-linked recessive disorder from his carrier mother. Since he receives one X chromosome from his mother, the probability is 50%.

Tags

NGSS.HS-LS3-1

For an autosomal dominant disorder, if one parent is heterozygous for the disorder and the other parent is homozygous normal, the probability that their child will be a carrier of the disorder is (a)   .

• 0%

• 25%

• 50%

• 100%

Answer explanation

The child has a 50% chance of inheriting the dominant allele from the heterozygous parent, making them a carrier of the disorder.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

In the case of mitochondrial inheritance, if a woman with a mitochondrial disorder has children, what percentage of her children are expected to inherit the disorder?

• 0%

• 25%

• 50%

• 100%

Answer explanation

Mitochondrial disorders are passed down from the mother to all her children, resulting in 100% of her children inheriting the disorder.