Question 1

Which of the following best describes the relationship between genes and chromosomes as depicted in the first image?

Accepted Answer

Genes are located on chromosomes, and each chromosome can carry many genes, with alleles representing different versions of a gene.

Question 2

If both parents are carriers for sickle cell disease (genotype HbA/HbS), what is the probability that their child will have sickle cell disease (HbS/HbS)?

Accepted Answer

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

Question 3

Which inheritance pattern is illustrated by the third image (autosomal recessive)?

Accepted Answer

Autosomal recessive

Question 4

A woman with genotype HbA/HbS and a man with genotype HbA/HbA have a child. What is the probability that the child will be a carrier for sickle cell disease?

Accepted Answer

$$\frac{1}{2}$$

Question 5

Which of the following best explains why X-linked recessive disorders are more common in males than females, as shown in the fifth image?

Accepted Answer

Males have only one X chromosome, so a single recessive allele will cause the disorder.

Question 6

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

Accepted Answer

Autosomal dominant

Question 7

If a father is affected by an X-linked dominant disorder and the mother is unaffected, what is the probability that their daughter will be affected?

Accepted Answer

$$1$$

Question 8

Which of the following is an example of codominance?

Accepted Answer

A person with type AB blood expressing both A and B antigens equally.

Question 9

A woman who is a carrier for hemophilia (X-linked recessive) marries a man who does not have hemophilia. What is the probability that their son will have hemophilia?

Accepted Answer

$$\frac{1}{2}$$

Question 10

Which of the following best describes pleiotropy?

Accepted Answer

A single gene affects multiple, seemingly unrelated traits.

Question 11

If two parents are both heterozygous for cystic fibrosis (an autosomal recessive disorder), what is the probability that their child will be unaffected (either carrier or non-carrier)?

Accepted Answer

$$\frac{3}{4}$$

Question 12

Which of the following statements about Mendel's law of segregation is correct?

Accepted Answer

Alleles for a trait separate during gamete formation, so each gamete receives only one allele.

Question 13

A child is born with Tay-Sachs disease, but neither parent shows symptoms. What are the most likely genotypes of the parents?

Accepted Answer

Both parents are heterozygous carriers.

Question 14

Which of the following best explains why most recessive inherited diseases are not evenly distributed in a population?

Accepted Answer

Recessive alleles are often hidden in carriers and may be more common in populations with high rates of consanguinity.

Question 15

Which of the following is an example of polygenic inheritance?

Accepted Answer

Human skin color, which is influenced by multiple genes.

Question 16

A man with type AB blood and a woman with type O blood have a child. What are the possible blood types for their child?

Accepted Answer

Type A or Type B

Question 17

Which of the following best describes the chromosome theory of inheritance?

Accepted Answer

Genes are located on chromosomes, and chromosomes are inherited as units during meiosis and fertilization.

Question 18

If a woman with Huntington's disease (autosomal dominant, genotype Hh) marries a man without the disease (hh), what is the probability that their child will inherit the disease?

Accepted Answer

$$\frac{1}{2}$$

Question 19

Which of the following is true about sex-linked inheritance?

Accepted Answer

Fathers pass their X chromosome to all daughters but not to sons.

Question 20

A pedigree shows a trait that skips generations and is more common in males. What is the most likely mode of inheritance?

Accepted Answer

X-linked recessive

Patterns of Inheritance: Mendelian and Non-Mendelian Genetics

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