Question 1

Which of the following best describes a dominant allele in the context of genetic inheritance?

Accepted Answer

An allele that masks the expression of a recessive allele in a heterozygote.

Question 2

A child inherits cystic fibrosis, a recessive genetic disease. What must be true about the parents' genotypes?

Accepted Answer

Both parents must carry at least one recessive allele.

Question 3

If $$A is a $$dominant allele and $$a is a $$recessive allele, which genotype will express the recessive phenotype?

Accepted Answer

$$aa$$

Question 4

Which equation represents the Hardy-Weinberg equilibrium for a gene with two alleles, $$p$$ and $$q$$?

Accepted Answer

$$p^2 + 2pq$$ + $$q^2 = 1$

Question 5

A population has allele frequencies $$p = 0.7$$ and $$q = 0.3. $$What is the expected frequency of heterozygotes under Hardy-Weinberg equilibrium?

Accepted Answer

$$0.42$$

Question 6

Which of the following is an example of a disease that is caused by a dominant allele?

Accepted Answer

Huntington's disease

Question 7

Why do some recessive alleles persist in populations despite being associated with disease?

Accepted Answer

Carriers of recessive alleles do not express the disease phenotype and can pass the allele to offspring.

Question 8

Which scenario best illustrates the concept of heterozygote advantage?

Accepted Answer

Individuals with one dominant and one recessive allele have increased resistance to malaria.

Question 9

If a genetic disease is caused by a recessive allele, what is the probability that two heterozygous parents will have an affected child?

Accepted Answer

$$1/4$$

Question 10

Which of the following statements about evolutionary benefits of genetic variation is correct?

Accepted Answer

Genetic variation increases the likelihood of survival in changing environments.

Question 11

A pedigree shows a trait that appears in every generation. What is the most likely pattern of inheritance?

Accepted Answer

Autosomal dominant

Question 12

Which of the following is NOT a possible genotype for a person with a dominant phenotype?

Accepted Answer

$$aa$$

Question 13

In a population, the frequency of allele $$A is$$ $$0.6$$ and allele $$a is$$ $$0.4. $$What is the expected frequency of individuals with genotype $$AA$$?

Accepted Answer

$$0.36$$

Question 14

Which of the following best explains why sickle cell anemia persists in certain populations?

Accepted Answer

Heterozygotes have a survival advantage in malaria-endemic regions.

Question 15

A woman is heterozygous for a dominant genetic disorder. What is the probability that her child will inherit the disorder if the father is homozygous recessive?

Accepted Answer

$$1/2$$

Question 16

Which of the following is a real-world example of a recessive genetic disorder?

Accepted Answer

Cystic fibrosis

Question 17

If two parents are both carriers for a recessive allele, what is the probability that their child will be a carrier?

Accepted Answer

$$1/2$$

Question 18

Which of the following is true about the inheritance of X-linked recessive diseases?

Accepted Answer

Males are more likely to express the disease because they have only one X chromosome.

Question 19

Which pattern of inheritance is most likely if a trait skips generations and affects both males and females equally?

Accepted Answer

Autosomal recessive

Question 20

Which of the following best describes the evolutionary benefit of carrying a recessive allele for a disease like sickle cell anemia?

Accepted Answer

Carriers have increased resistance to malaria.

Patterns of Genetic Inheritance: Dominant and Recessive Alleles, Diseases, and Evolutionary Benefits

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