Question 1

Which of the following statements best describes mitochondrial inheritance?

Accepted Answer

It is inherited exclusively from the mother and affects both males and females.

Question 2

A pedigree shows a trait that appears in every generation and affects males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 3

Which of the following diseases is caused by a mutation in the beta-globin gene, resulting in abnormal hemoglobin structure?

Accepted Answer

Sickle cell disease

Question 4

If both parents are heterozygous for an autosomal recessive trait, what is the probability that their child will be affected by the trait?

Accepted Answer

$$\frac{1}{4}$$

Question 5

Which molecular change is responsible for sickle cell disease?

Accepted Answer

A substitution of glutamic acid with valine at position 6 of the beta-globin chain

Question 6

A man and woman, both heterozygous for the sickle cell allele, have two children. What is the probability that neither child will develop sickle cell disease?

Accepted Answer

$$0.5625$$

Question 7

Which of the following is a key feature of autosomal recessive inheritance in pedigrees?

Accepted Answer

Traits often skip generations and appear equally in both sexes.

Question 8

Huntington disease is caused by which type of genetic mutation?

Accepted Answer

A trinucleotide (CAG) repeat expansion in the HTT gene

Question 9

Which of the following best explains why mitochondrial DNA is inherited maternally?

Accepted Answer

Sperm mitochondria are destroyed after fertilization, so only the mother's mitochondria are passed on.

Question 10

A pedigree shows a trait that is present only in children of affected mothers, regardless of the father's phenotype. What is the most likely mode of inheritance?

Accepted Answer

Mitochondrial

Question 11

Which of the following is NOT a characteristic of autosomal dominant inheritance?

Accepted Answer

Traits are more common in males than females.

Question 12

Which of the following diseases is an example of an autosomal recessive disorder?

Accepted Answer

Tay-Sachs disease

Question 13

What is the function of hemoglobin in red blood cells?

Accepted Answer

To transport oxygen from the lungs to cells in the body

Question 14

Which of the following best describes the molecular basis of Tay-Sachs disease?

Accepted Answer

A deficiency in the enzyme hexosaminidase A, leading to accumulation of GM2 ganglioside

Question 15

If a woman with a mitochondrial disorder has children with a healthy man, what is the probability that her children will inherit the disorder?

Accepted Answer

$$1$$

Question 16

Which process is responsible for the expansion of nucleotide repeats, such as those seen in Huntington disease?

Accepted Answer

Incorrect DNA repair after polymerase slippage during replication

Question 17

A pedigree shows consanguineous parents with an affected child. Which inheritance pattern is most likely?

Accepted Answer

Autosomal recessive

Question 18

Which of the following statements about mitochondrial DNA is TRUE?

Accepted Answer

It is replicated, transcribed, and translated independently from chromosomal DNA.

Question 19

A child is born to two unaffected parents and is affected by an autosomal recessive disorder. What are the most likely genotypes of the parents?

Accepted Answer

Both parents are heterozygous carriers.

Question 20

Which of the following is a feature of Huntington disease inheritance?

Accepted Answer

It is caused by a trinucleotide repeat expansion and is autosomal dominant.

Inheritance Patterns Sep 5

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