Question 1

Which of the following best describes the Law of Segregation as established by Mendel?

Accepted Answer

The two alleles of each gene separate during gamete formation and end up in different gametes.

Question 2

A woman with genotype $$Ff ($$freckles) and a man with genotype $$ff (no $$freckles) have a child. What is the probability that their child will have freckles?

Accepted Answer

$$0.50$$

Question 3

Which of the following is an example of incomplete dominance?

Accepted Answer

A person with genotype $$Hh$$ has wavy hair, intermediate between straight ($$HH) $$and curly ($$hh) $$hair.

Question 4

Which of the following statements about codominance is correct?

Accepted Answer

Codominance occurs when both alleles in a heterozygote are fully expressed, as in blood type $$AB.$$

Question 5

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

Accepted Answer

$$0.50$$

Question 6

Which of the following best explains why individuals heterozygous for the sickle cell allele are less likely to die from malaria?

Accepted Answer

They produce both normal and sickle cell hemoglobin, which provides resistance to malaria.

Question 7

Which of the following is a correct statement about polygenic inheritance?

Accepted Answer

Polygenic traits are usually distributed within a population as a continuous range of values.

Question 8

A child is born with Down syndrome. Which chromosomal abnormality is responsible for this condition?

Accepted Answer

Trisomy 21

Question 9

Which of the following best describes the effect of environmental factors on phenotype?

Accepted Answer

Environmental factors can influence gene expression without altering the DNA sequence.

Question 10

A woman with genotype $$X^N X^n ($$carrier for hemophilia) and a man with genotype $$X^N Y ($$normal) have a daughter. What is the probability that the daughter will be a carrier for hemophilia?

Accepted Answer

$$0.50$$

Question 11

Which of the following is true regarding nondisjunction during meiosis?

Accepted Answer

It can result in gametes with an abnormal number of chromosomes, leading to conditions such as Down syndrome.

Question 12

Which of the following is an example of a dominant allele causing a disease phenotype?

Accepted Answer

Huntington disease

Question 13

If a person has the genotype $$AB$$ for the ABO blood group, which antigens will be present on their red blood cells?

Accepted Answer

Both A and B antigens

Question 14

Which of the following best describes a karyotype?

Accepted Answer

A display of an individual's chromosomes arranged in pairs from largest to smallest.

Question 15

Which of the following is a likely outcome if a male inherits an X-linked recessive allele from his mother?

Accepted Answer

He will express the trait because he has only one X chromosome.

Question 16

Which of the following best explains why most people with polydactyly (extra fingers or toes) are rare, even though the allele is dominant?

Accepted Answer

Dominant does not refer to frequency; the polydactyly allele is simply rare in the population.

Question 17

A person with genotype $$Hh$$ for familial hypercholesterolemia has blood cholesterol levels 2-3 times normal. What type of inheritance does this illustrate?

Accepted Answer

Incomplete dominance

Question 18

Which of the following is a possible result of a chromosomal deletion?

Accepted Answer

Cri-du-chat syndrome

Question 19

Which of the following best describes epigenetic inheritance?

Accepted Answer

It involves modifications to DNA or histones that affect gene expression without changing the DNA sequence.

Question 20

A man with genotype $$XY$$ and a woman with genotype $$XX$$ have a child. What is the probability that the child will be male?

Accepted Answer

$$0.50$$

Genetics and Inheritance: Human Biology Study Notes

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