Deck 4: Extensions of Mendelian Inheritance

Question 1

A woman who is heterozygous for pattern baldness marries a man who is nonbald. Which of the following would be true of their offspring?

A) All would be bald
B) All of the females would be nonbald, all males would be bald
C) All of the females would be nonbald, ½ of the males would be bald
D) ½ of females would be bald, and ½ of the females would be bald
E) All would be nonbald

Answer 1

C

Question 2

At the molecular level, type A and type B blood differ in which of the following characteristics?

A) The antigens present on the surface of the red blood cells
B) The type of sugar found in each type
C) The antibodies that are generated against the other type of blood
D) All of the answers are correct

Answer 2

D

Question 3

If an allele is dominant in one sex and recessive in another, it is an example of .

A) Sex-limited inheritance
B) Sex-influenced inheritance
C) Incomplete dominance
D) Simple Mendelian inheritance
E) Incomplete dominance

Answer 3

B

Question 4

The coat characteristics of Siamese cats and Himalayan rabbits, where proteins in the extremities function differently than in other parts of the body is an example of .

A) Incomplete dominance
B) Multiple allele systems
C) Semilethal alleles
D) Temperature-sensitive allele
E) None of the answers are correct

Question 5

A heterozygote possesses a phenotype that is intermediate between the homozygous dominant and homozygous recessive phenotypes. This is most likely an example of .

A) Lethal alleles
B) Incomplete dominance
C) Gene dosage
D) Sex-influenced inheritance

Question 6

Huntington disease in humans is an example of .

A) Essential genes
B) Lethal alleles
C) Semilethal alleles
D) Nonessential genes
E) Conditional lethal alleles

Question 7

Temperature-sensitive alleles are examples of .

A) Essential genes
B) Lethal alleles
C) Semilethal alleles
D) Nonessential genes
E) Conditional lethal alleles

Question 8

The interaction of two genes to produce a phenotype was first described by .

A) Morgan and Bridges
B) Mendel
C) Darwin
D) Bateson and Punnett
E) None of the answers are correct

Question 9

An individual with type A blood and an individual with type B blood mate and have offspring. What blood type is not possible in their offspring?

A) Type O blood
B) Type A blood
C) Type B blood
D) Type AB blood
E) All blood types are possible

Question 10

Genes that are not required for survival, but are likely to be beneficial to the organism, are called .

A) Essential genes
B) Lethal alleles
C) Semilethal alleles
D) Nonessential genes
E) Conditional lethal alleles

Question 11

If a geneticist describes a trait as being 70% penetrant, what would they mean?

A) The expression of the trait varies by individual
B) It is lethal in 30% of the individuals who have the trait
C) Only 70% of the individuals who carry the trait express the trait
D) The trait is present in 70% of the population

Question 12

Sickle-cell anemia in humans is an example of .

A) Codominance
B) Incomplete penetrance
C) Heterozygous advantage
D) Multiple allele systems
E) None of the answers are correct

Question 13

Phenylketonuria in humans is an example of .

A) Incomplete penetrance
B) Codominance
C) An environmental-influenced trait
D) Incomplete dominance
E) All of the answers are correct

Question 14

In four-o'clock plants, red flower color is dominant to white flower color. However, heterozygous plants have a pink color. If a pink-flowered plant is crossed with a white-flowered plant, what will be the phenotypic ratios of their offspring?

A) ¼ red, ½ pink, ¼ white
B) All pink
C) All white
D) ½ pink, ½ white
E) ½ red, ½ pink

Question 15

In human blood groups, the fact that an individual can have an AB blood type is an example of .

A) Incomplete dominance
B) Incomplete penetrance
C) Sex-influenced trait
D) Temperature-sensitive conditional allele
E) Codominance

Question 16

At the molecular level, which of the following best explain heterozygous advantage and over dominance?

A) A heterozygous individual can produce more varieties of homodimer proteins
B) The alleles produce two different proteins with slightly different functions
C) The proteins produced by the alleles may provide a broader range of environmental tolerance, such as temperature ranges
D) Infectious organisms may recognize only a specific functional protein
E) All of the answers are possibilities

Question 17

Male-pattern baldness is a sex-linked trait in humans.

Question 18

In rabbits, full coat color (c) is the dominant trait. A second allele, chinchilla (cch) is recessive to full coat color. Himalayan coat color (ch) is recessive to chinchilla and full coat colors and albino (c)
Is recessive to all coat colors. If two chinchilla rabbits mate, what coat color is not possible in their offspring?

A) Full coat color
B) Chinchilla coat color
C) Himalayan coat color
D) Albino coat color
E) All coat colors are possible

Question 19

For a certain trait, a heterozygous individual has a selective advantage than a homozygous dominant or homozygous recessive individual. This is called .

A) Codiminance
B) Incomplete dominance
C) Over dominance
D) Incomplete penetrance
E) Multiple allele systems

Question 20

Polydactyly in humans is an example of .

A) Simple Mendelian inheritance
B) Incomplete dominance
C) Incomplete penetrance
D) Codominance
E) Gene dosage

Question 21

Epistasis is .

A) Another term for over dominance
B) When one gene can mask the expression of a second gene
C) A trait that is only expressed in one sex of the species
D) When two dominant alleles can be expressed in the same individual
E) None of the answers are correct

Question 22

Human blood groups are determined by antigens on the surface of red blood cells.

Question 23

The multiple effects of a single gene on the phenotype of an organism is called .

A) Epistasis
B) penetrance
C) Expressivity
D) Overdominance
E) Pleiotropy

Question 24

A allele encodes a protein that is made in the proper amount and functions normally.

A) loss-of-function
B) mutant
C) wild-type
D) gain-of-function
E) lethal

Question 25

In humans, pattern baldness follows a sex-influenced pattern of inheritance. A heterozygous male has the phenotype and a heterozygous female has a phenotype.

A) Y-linked, X-linked
B) nonbald, bald
C) X-linked, Y-linked
D) bald, nonbald
E) none of the above

Question 26

In overdominance, the genotype is beneficial over the genotypes.

A) heterozygous, homozygous
B) homozygous, heterozygous
C) homozygous dominant, homozygous recessive
D) homozygous recessive, homozygous dominant
E) incomplete dominant, codominant

Question 27

Typically, a recessive allele increases the expression of a functional protein.

Question 28

If a combination of two or more genes is required to produce a specific trait, it is called a .

A) overdominance
B) simple mendelian trait
C) sex-influenced trait
D) sex-linked trait
E) gene interaction

Question 29

A suppressor mutation

A) Can only be found in the same gene
B) Can only be found in a separate gene
C) Can be found in the same gene or a separate gene
D) Cannot be created
E) None of the answers are correct

Question 30

The trait of cream-colored eyes in Drosophila is an example of .

A) Simple recessive alleles
B) Incomplete penetrance of red eyes
C) Gene interactions in eye color
D) Gene dosage
E) A spontaneous mutation

Question 31

The coat color of rabbits is an example of a(n) .

A) Semilethal allele
B) Sex-linked trait
C) Multiple allele system
D) Incomplete dominance

Question 32

In an epistatic interaction, the genes must be located on the same chromosome.

Question 33

Which of the following is not correct concerning epistatic interactions?

A) They are often associated with enzymatic pathways
B) They produce variations in the expected 9:3:3:1 ratio of a dihybrid cross
C) They can result when a gene at one locus masks the expression of a gene at a different locus
D) They always result in a 9:7 ratio of a dihybrid cross
E) They are due to gene interactions

Question 34

When wild-type offspring are produced from a cross between parents that both display the same recessive phenotype illustrates the genetic phenomenon of .

A) Simple recessive alleles
B) Incomplete penetrance
C) Complementation
D) Gene dosage
E) A spontaneous mutation

Question 35

Incomplete penetrance indicates that individuals who possess a dominant trait always express the trait.

Question 36

In a dihybrid cross of two heterozygous individuals, you expect a 9:3:3:1 phenotypic ratio in the offspring, but observe a ratio of 9:7. What is the most likely explantation?

A) Codominace
B) It is a sex-limited trait
C) Simple Mendelian inheritance
D) Incomplete penetrance
E) Epistatic interactions of the two genes

Question 37

Incomplete dominance is an example of blending of phenotypes, not genotypes.

Question 38

Paralogs are often functionally redundant and can compensate for the loss of either of the paralogs in a
set.

Question 39

Variable expressivity means that the phenotype of a trait can vary between individuals.

Question 40

How did Bateson and Punnett's work with comb morphology in chickens differ from the dihybrid work of Mendel?

A) They were working with sex-limited traits
B) Their F2 offspring displayed 4 unique phenotypes, not the four combinations of two phenotypes expected in a Mendelian cross
C) ½ of their combinations were lethal
D) The expression of their trait varied by the environment in which the chickens were raised

Question 41

If a light-eosin eye male Drosophila is crossed to a homozygous red eyed female, what will be the phenotype of their offspring?

A) All offspring will have red eyes
B) All males will be light-eosin and all females will be eosin
C) All females will have red eyes, all males will have light-eosin eyes
D) All flies will have white eyes
E) None of the answers are correct