Question 1

Which of the following best describes incomplete dominance?

Accepted Answer

The heterozygote displays a phenotype intermediate between the two homozygotes.

Question 2

A cross between two snapdragons, one with genotype $C^R C^W$ and one with genotype $C^W C^W$, will produce offspring with which phenotypic ratio?

Accepted Answer

$1$ pink : $1$ white

Question 3

Which scenario is an example of pleiotropy?

Accepted Answer

A gene that affects both red blood cell shape and kidney function.

Question 4

In the ABO blood group system, which genotype(s) will result in blood type AB?

Accepted Answer

$I^A I^B$

Question 5

Which of the following best explains why colorblindness is more common in males than females?

Accepted Answer

Colorblindness is caused by a recessive allele on the X chromosome, and males have only one X chromosome.

Question 6

Which inheritance pattern is responsible for the wide range of human skin colors?

Accepted Answer

Polygenic inheritance

Question 7

In Labrador retrievers, the E/e gene is epistatic to the B/b gene. What is the expected phenotypic ratio in the offspring of a cross between two BbEe dogs?

Accepted Answer

$9$ black : $3$ brown : $4$ yellow

Question 8

A woman with genotype $Aa$ (carrier for albinism) and a man with genotype $AA$ (normal) have a child. What is the probability that their child will be a carrier for albinism?

Accepted Answer

$1/2$

Question 9

Which of the following is a key feature of epigenetic regulation?

Accepted Answer

Chemical modifications to DNA or histones that affect gene accessibility.

Question 10

A child is born with sickle cell anemia. Which of the following best describes the genetic basis of this disease?

Accepted Answer

It is caused by a recessive allele with pleiotropic effects.

Question 11

Which of the following best describes codominance?

Accepted Answer

Both alleles are fully and separately expressed in the phenotype.

Question 12

A cross between two $AaBbCc$ individuals (for skin color) produces offspring with a range of skin shades. What is the expected distribution of phenotypes?

Accepted Answer

A continuous, normal distribution of skin shades.

Question 13

Which of the following is an example of environmental impact on phenotype?

Accepted Answer

Hydrangea flowers change color depending on soil pH.

Question 14

In a pedigree analysis, which pattern would suggest a recessive trait?

Accepted Answer

Trait often skips generations and appears in siblings whose parents do not show the trait.

Question 15

Which equation best represents the probability of a child inheriting a dominant trait from two heterozygous parents?

Accepted Answer

$P = 3/4$

Question 16

Which of the following is true about Huntington's disease?

Accepted Answer

It is a dominantly inherited disorder.

Question 17

A cross between two mice with genotype $Aa$ for the agouti gene results in offspring. If $BB$ homozygotes die early, what is the expected ratio of live agouti to yellow mice?

Accepted Answer

$2:1$ agouti:yellow

Question 18

Which of the following best describes polygenic inheritance?

Accepted Answer

Multiple genes contribute additively to a single trait.

Question 19

Which of the following is a real-world example of epigenetic modification affecting phenotype?

Accepted Answer

Genetically identical bees developing into queens or workers depending on diet.

Question 20

Which formula would you use to calculate the probability of a child inheriting two recessive alleles from heterozygous parents?

Accepted Answer

$P = 1/2 	imes 1/2 = 1/4$

Inheritance Patterns and Human Genetic Disease: Mendelian and Non-Mendelian Genetics

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