Question 1

Matt buys a male python from a snake dealer who tells him that the snake carries the albino allele. What is the most effective way for Morgan to verify this statement?

Accepted Answer

A)  Breed the snake with a heterozygous female. 
B)  Breed the snake with a homozygous normal female. 
C)  Breed the snake with a female sibling. 
D)  Breed the snake with a homozygous recessive albino female. 
E)  He can breed the snake with any female, and a portion of the offspring will always be albino.

Question 2

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)

Question 3

Which of the following is a true statement?

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 inherit two copies of the SRY gene. 
D)  The X and Y chromosomes are homologous. 
E)  Men pass their X-linked traits to their sons.

Question 4

Which variable(s) will determine the coat color of a Himalayan rabbit?

Accepted Answer

A)  only genetics 
B)  only the environmental temperature 
C)  both genetics and environmental temperature 
D)  neither genetics or environmental temperature

Question 5

The garden pea was a good model for Mendel's genetics experiments. Which of the following is a true statement regarding this model organism?

Accepted Answer

A)  The plants were easy to grow. 
B)  Pea plants can either cross-pollinate or self-pollinate. 
C)  All inheritance patterns were simple. 
D)  Most of the traits studied had no intermediate stage. 
E)  All of the above are true statements.

Question 6

Matt buys a male python from a snake dealer who tells him that the snake carries the albino allele. Matt mates the snake with an albino female, and four normally pigmented offspring are produced. Matt rushes back to the snake dealer and demands his money back stating that the male he bought is not heterozygous for the albino allele because all of its offspring had normal pigmentation. Is Matt justified in his accusation?

Accepted Answer

A)  Yes, because according to the laws of probability, at least one of the offspring should have been albino. 
B)  Yes, because 50% of all offspring produced must be albino. 
C)  No, because for each offspring, there is a 50% chance that it will have normal pigmentation. 
D)  No, because a heterozygous male will only pass the dominant allele to its offspring. 
E)  Yes, because if at least one parent is homozygous recessive, at least one of their offspring must also show the recessive trait.

Question 7

In a dihybrid cross where both parents are heterozygous, the expected phenotypic ratio is

Accepted Answer

A)  1:2:1. 
B)  9:3:3:1. 
C)  1:1:1. 
D)  3:1. 
E)  1:1:1:1.

Question 8

Determine if the following statement is true or false. 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 be heterozygous. 
D)  False, because both parents could be heterozygous. 
E)  True, because both parents have the dominant allele.

Question 9

Alport syndrome, a dominantly inherited X-linked disorder, is characterized by glomerulonephritis, end-stage kidney disease, and hearing loss. A mother with alport disease, whose father was unaffected, marries an unaffected man. What are the chances that she would give birth to a son with alport syndrome?

Accepted Answer

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

Question 10

Which of the following is true about an individual with the chromosomes shown in this figure?

Accepted Answer

A)  All offspring will have the dominant phenotype for each trait. 
B)  All offspring will have the recessive phenotype for each trait. 
C)  The individual is homozygous for all traits. 
D)  The individual is heterozygous for all traits. 
E)  The individual is homozygous for at least one trait.

Question 11

What are all possible gametes that can be produced by an individual with the following genotype:FFGg?

Accepted Answer

A)  FG, Fg 
B)  FF, Gg 
C)  Fg 
D)  FG, Fg, fG, fg 
E)  Fg, fG

Question 12

In a one-trait testcross, a homozygous dominant individual is crossed with a homozygous recessive individual. Which phenotype will be absent in the F 1 generation?

Accepted Answer

A)  dominant trait. 
B)  negative trait. 
C)  recessive trait. 
D)  heterozygote. 
E)  homozygote.

Question 13

Megan has a widow's peak (dominant trait) and attached earlobes (recessive trait). Megan's dad has a straight hairline and unattached earlobes. What is Megan's genotype?

Accepted Answer

A)  WWEE 
B)  WwEE 
C)  wwee 
D)  WwEe 
E)  Wwee

Question 14

Both parents are heterozygous for Tay-Sachs disease (an autosomal recessive disorder). Three children in a row were born with Tay-Sachs disease. What is the chance that a fourth child will have Tay-Sachs disease?

Accepted Answer

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

Question 15

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 16

If a true-breeding tall pea plant is crossed with a tall pea plant of unknown parentage, which of the following is correct?

Accepted Answer

A)  All of the offspring (F 1) will be short. 
B)  Over several generations, no short individuals will appear. 
C)  Some short individuals may appear in the F 2 generation. 
D)  It is impossible to determine based on the information provided. 
E)  Some of the F 1 generation will be short.

Question 17

Megan has a widow's peak (dominant trait) and attached earlobes (recessive trait). Megan's dad has a straight hairline and unattached earlobes. If Megan 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 18

If the parental genotype is EeWw, what are the potential allele combinations that could occur at the end of meiosis?

Accepted Answer

A)  EW, Ew, eW, and ew 
B)  EW, EE, eW, and ww 
C)  WW, Ew, EW, and ew 
D)  EE, WW, ee, and ww 
E)  EW, Ew, ee and ww

Question 19

If an individual expresses a dominant disease, which of the following is true?

Accepted Answer

A)  All of his children will always inherit the disease. 
B)  He will pass this disease to all of his daughters. 
C)  There is at least a 50% probability that his children will inherit the disease. 
D)  There is a 100% possibility that his sons will inherit this disease. 
E)  None of his children will inherit the disease unless his wife also has the disease.

Question 20

During meiosis, each pair of alleles on the homologous chromosomes sorts independently from all other pairs of alleles. This statement corresponds to

Accepted Answer

A)  the rule of multiplication. 
B)  the law of segregation. 
C)  the law of probability. 
D)  gene theory. 
E)  the law of independent assortment.

Exam 10: Patterns of Inheritance