Question 1

The garden pea was a good model for Mendel's genetics experiments. Which of the following is not true regarding this model organism?

Accepted Answer

A)  The plants were easy to grow. 
B)  Pea plants can either cross-pollinate or self-pollinate. 
C)  There was only one variety of pea available to Mendel. 
D)  All inheritance patterns were simple. 
E)  Most of the traits studied had no intermediate stage.

Question 2

Parents with the dominant phenotype cannot have offspring with the recessive phenotype.

Accepted Answer

A)  True, because the dominant gene must be passed down from each parent. 
B)  True, because at least one dominant gene will be passed down from each parent. 
C)  False, because one parent could carry the recessive allele. 
D)  False, because both parents could carry the recessive allele. 
E)  True, because both parents have the dominant allele.

Question 3

A homozygous red-eyed female Drosophila mates with a red-eyed male Drosophila. What proportion of the female offspring will have white eyes?

Accepted Answer

A)  0% 
B)  25% 
C)  50% 
D)  75% 
E)  100%

Question 4

Which of the following is an example of a phenotype?

Accepted Answer

A)  AAGg 
B)  freckles 
C)  AA 
D)  Ag 
E)  Gg

Question 5

Vitamin-D resistant rickets is a sex-linked dominant trait, which leads to softening of the bones, which can cause fractures and deformities. Rickets is often due to a deficiency of vitamin D; however, with vitamin- D resistant rickets, ingestion of vitamin D is ineffective. Maria's mother is normal and does not display any symptoms of this disease. Maria's father, however, has the disease. Maria marries a man that does not have the disease. What is the probability that they will have a daughter that has the disease?

Accepted Answer

A)  0% 
B)  25% 
C)  50% 
D)  75% 
E)  100%

Question 6

Amy has wavy hair and 6 fingers an autosomal dominant trait). Wavy hair is inherited through incomplete dominance. Which of the following combinations are possible for her parents?

Accepted Answer

A)  5 only 
B)  1 and 2 
C)  1, 3, and 4 
D)  2, 4, and 5 
E)  2 and 4

Question 7

The filled-in squares of a Punnett square represent

Accepted Answer

A)  the gametes from both parents. 
B)  all possible combinations of gametes based on a cross between the two parents. 
C)  an exact ratio that must always occur when the same parents have four offspring. 
D)  examples of some of the offspring that can arise from a one-trait cross. 
E)  the gametes from one parent.

Question 8

Which of the following is true?

Accepted Answer

A)  Females can be heterozygous for sex-linked traits. 
B)  All traits on the sex chromosomes are associated with sexual development. 
C)  Males are heterozygous for the SRY gene. 
D)  The X and Y chromosomes are homologous. 
E)  Men pass their X-linked traits to their sons.

Question 9

Primroses have white flowers when grown above 32°C but red flowers when grown at 24°C. This interaction between phenotypic expression and environment is an example of

Accepted Answer

A)  epistasis. 
B)  polygenic traits. 
C)  pleiotropy. 
D)  multiple allelism. 
E)  codominance.

Question 10

Morgan breeds and sells snakes. He knows that he can make the most money by breeding and selling albino snakes. Albinism is a recessive trait. His female albino corn snake just produced six offspring. Two displayed normal coloration and four were albino. What is the chance that another offspring produced by the same parents will be albino?

Accepted Answer

A)  0% 
B)  25% 
C)  50% 
D)  75% 
E)  100%

Question 11

Which variable will determine the coat color in Himalayan rabbits?

Accepted Answer

A)  the genetics will determine it 100% 
B)  the environment will determine it 100% 
C)  both the genetics and environment will determine the coat color 
D)  neither the environment nor genes will play a role in determining coat color

Question 12

Traits that are controlled by several sets or pairs of alleles, such as skin color and height in humans, are the result of what form of inheritance?

Accepted Answer

A)  polygenic 
B)  incomplete dominance 
C)  multiple allele systems 
D)  simple Mendelian inheritance 
E)  codominance

Question 13

Unattached earlobes EE or Ee) are dominant over attached earlobes ee). A couple both have unattached earlobes. Both notice that one of their parents on both sides have attached earlobes ee). Therefore, they correctly assume that they are carriers for attached earlobes Ee). If the couple proceeds to have four children, then

Accepted Answer

A)  they can be certain that three will be heterozygous and one homozygous recessive. 
B)  if the first three are heterozygous, the fourth must be homozygous recessive. 
C)  the children must repeat the grandparents'genotype Ee). 
D)  all children must have unattached earlobes since both parents possess the dominant gene for it. 
E)  two heterozygous, one homozygous dominant, and one homozygous recessive is a likely outcome, but all heterozygous, or two, three, or all four homozygous is also possible.

Question 14

If both parents express a particular trait, but their child does not, what does this indicate about the trait?

Accepted Answer

A)  The trait is an autosomal dominant trait. 
B)  The trait is an autosomal recessive trait. 
C)  The trait is sex-linked recessive. 
D)  The trait is sex-linked dominant. 
E)  This is a lethal trait.

Question 15

Martha has a widow's peak dominant trait) and attached earlobes recessive trait). Martha's dad had a straight hairline and unattached earlobes. If Martha marries a man that is heterozygous for both traits, what is the probability that they will have a child with a widow's peak and attached earlobes?

Accepted Answer

A)  1/16 
B)  3/8 
C)  1/4 
D)  1/2 
E)  3/4

Question 16

Alleles that are linked on the same chromosome will assort independently during meiosis.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following is not a correct match?

Accepted Answer

A)  physical expression of a trait - phenotype 
B)  allele that masks the expression of an alternate allele - dominant 
C)  identical alleles - heterozygous 
D)  allele whose expression can be masked by an alternate allele - recessive 
E)  the specific alleles that an individual has - genotype

Question 18

Red-green color blindness is a recessive X-linked trait. If a female is red-green color-blind, which of the following is true?

Accepted Answer

A)  Her mother must be color-blind. 
B)  Both her parents must be color-blind. 
C)  Both her parents are carriers of the recessive allele. 
D)  Her father must be color-blind. 
E)  Women cannot exhibit red-green color blindness because they have two X chromosomes.

Question 19

What does true-breeding mean?

Accepted Answer

A)  When the plant is pollinated, all the offspring resemble the parent and are heterozygotes. 
B)  The organism can be cross-pollinated. 
C)  When the plant self-pollinates, all the offspring resemble the parent, and are homozygous for that gene. 
D)  The organism is easy to cultivate. 
E)  The organism cannot be cultivated.

Question 20

Which genetic disorder is associated with an irregular shape of the red blood cells?

Accepted Answer

A)  sickle-cell disease 
B)  Marfan syndrome 
C)  Huntington disease 
D)  phenylketonuria PKU) 
E)  cystic fibrosis CF)

Exam 10: Patterns of Inheritance

The garden pea was a good model for Mendel's genetics experiments. Which of the following is not true regarding this model organism?

Parents with the dominant phenotype cannot have offspring with the recessive phenotype.

A homozygous red-eyed female Drosophila mates with a red-eyed male Drosophila. What proportion of the female offspring will have white eyes?

Which of the following is an example of a phenotype?

Amy has wavy hair and 6 fingers an autosomal dominant trait) . Wavy hair is inherited through incomplete dominance. Which of the following combinations are possible for her parents?

The filled-in squares of a Punnett square represent

Which of the following is true?

Primroses have white flowers when grown above 32°C but red flowers when grown at 24°C. This interaction between phenotypic expression and environment is an example of

Which variable will determine the coat color in Himalayan rabbits?

Traits that are controlled by several sets or pairs of alleles, such as skin color and height in humans, are the result of what form of inheritance?

If both parents express a particular trait, but their child does not, what does this indicate about the trait?

Alleles that are linked on the same chromosome will assort independently during meiosis.

Which of the following is not a correct match?

Red-green color blindness is a recessive X-linked trait. If a female is red-green color-blind, which of the following is true?

What does true-breeding mean?

Which genetic disorder is associated with an irregular shape of the red blood cells?