Deck 2: Transmission Genetics

Question 1

A couple has four children. What is the probability that they have four boys?

A) 1/2
B) 1/16
C) 1/4
D) 1/32
E) 1/8

Answer 1

B

Question 2

The gene L determines hair length in rabbits. The gene B determines hair color. A rabbit with long, black hair is crossed to a rabbit with short, white hair. All the offspring have long, black hair. What are the genotypes of the parents?

A) LLBB × llbb
B) Llbb × llBb
C) LlBb × LlBb
D) LlBb × llbb
E) Impossible to determine from the information given

Answer 2

A

Question 3

By convention, when an OBSERVED experimental outcome has a probability of occurrence of less than 5% (<0.05), the experimental results are considered to be .

A) not significant
B) statistically significant and different from the expected outcome
C) less than one standard deviation from the mean
D) within normal expected range
E) equal to the mean

Answer 3

B

Question 4

The statistical interpretation of a chi- square value is determined by identifying the .

A) joint probability
B) average
C) P value
D) mean
E) degrees of freedom

Question 5

In peas, the yellow allele is dominant over the green allele. A plant with yellow peas was crossed to a plant with green peas. The resulting plants were 50% yellow and 50% green. What are the genotypes of the parents in this cross?

A) yy × yy
B) Yy × yy
C) YY × yy
D) Yy × Yy
E) YY × Yy

Question 6

What phenotypic ratio would you expect as a result of a test cross between two individuals where one that is homozygous recessive for alleles at two independent loci?

A) 3:1
B) 1:2:1
C) 9:3:3:1
D) 1:1:1:1
E) 9:4:2:1

Question 7

If a plant with purple, axial flowers and green, inflated pods is heterozygous for all four genes, how many different types of gametes can it produce?

A) 4
B) 16
C) 1
D) 8
E) 9

Question 8

Humans have a gene, T, that is involved in muscle formation of the tongue. Individuals homozygous for one allele can roll their tongues, while individuals homozygous for the other allele cannot. If both parents can roll their tongues, but their child cannot, what can be said about the mode of inheritance?

A) The parents were both homozygous, but the child was heterozygous.
B) Tongue rolling is recessive, and both parents were heterozygous (Tt).
C) Tongue rolling is recessive.
D) Tongue rolling is dominant.
E) Tongue rolling is dominant, and both parents were heterozygous (Tt).

Question 9

Assuming independent assortment, what phenotypic ratio would you expect to see if an individual with the genotype RrGg is self- crossed?

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

Question 10

In peas, axial (A) flower position is dominant to terminal (a), and tall (L) is dominant to short (l). If a plant that is heterozygous for both traits is allowed to self- fertilize, how many of the offspring would also be heterozygous for both traits?

A) 1/8
B) 1/4
C) 3/16
D) 9/16
E) 1/16

Question 11

What genotypic ratio would you expect to observe among the progeny of a monohybrid cross?

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

Question 12

The P value is a quantitative expression of the probability that the results of another experiment of the same size and structure will DEVIATE FROM EXPECTED RESULTS AS MUCH AS OR MORE THAN BY CHANCE. The greater the difference between observed and expected results of an experiment, .

A) the lower the ç2 value and the lower the P value
B) the lower the ç2 value and the greater the P value
C) the greater the ç2 value; but the P value is unaffected
D) the greater the ç2 value and the greater the P value
E) the greater the ç2 value and the lower the P value

Question 13

Genetic crosses in which F1 plants heterozygous for a given allele are crossed to generate a 3:1 phenotypic ratio in the F2 generation are known as .

A) test crosses
B) dihybrid crosses
C) reciprocal crosses
D) monohybrid crosses
E) replicate crosses

Question 14

In rabbits, long hair and black fur are produced by the dominant alleles L and B, which assort independently. The genotype ll produces short hair and the genotype bb produces white fur. A cross between a male with short, black fur and a female with long, white fur produces four offspring with short, black fur, four offspring with long, white fur, four offspring with short, white fur, and four offspring with long, black fur. What are the genotypes of the parents?

A) LlBb × LlBb
B) LLBB × llbb
C) llBb × Llbb
D) llBB × LLbb
E) Impossible to determine from the information given.

Question 15

In peas, the smooth allele is dominant over the wrinkled allele. A plant with round peas was crossed to a plant with wrinkled peas and all of the resulting plants had smooth peas. What are the genotypes of the parents in this cross?

A) Rr × Rr
B) rr × rr
C) RR × Rr
D) Rr × rr
E) RR × rr

Question 16

In peas, axial (A) flower position is dominant to terminal (a), tall (L) is dominant to short (l), and yellow (Y) is dominant to green (y). If a plant that is heterozygous for all three traits is allowed to self- fertilize, how many of the offspring would show the dominant phenotype for all three traits?

A) 3/64
B) 32/64
C) 27/64
D) 9/64
E) 64/64

Question 17

You count 1000 F2 seeds from a monohybrid cross. How many seeds do you expect to display the dominant phenotype?

A) 750
B) 1000
C) 0
D) 500
E) 250

Question 18

In Guinea pigs, short hair (S) is dominant over long hair (s), rough coat (R) is dominant over smooth coat (r), and black hair (B) is dominant over white hair (b). Which of the following individuals could produce these (and only these) four possible gametes: SRb, Srb, sRb, srb.

A) SsRrbb
B) SSRrBb
C) SSRRbb
D) ssRrBB
E) SsRrBb

Question 19

In mice, black coat color is dominant to white coat color. In the pedigree below, mice with a black coat are represented by darkened symbols, and those with white coats are shown as open symbols. What is the probability that I- 1, I- 2, II- 2, AND III- 1 are all heterozygous?

A) 2/3
B) 1/2
C) 0
D) 1
E) 1/4

Question 20

In mice, black coat color is dominant to white coat color. In the pedigree below, mice with a black coat are represented by darkened symbols, and those with white coats are shown as open symbols. What is the genotype of III- 1?

A) heterozygous or homozygous recessive
B) heterozygous
C) homozygous recessive
D) homozygous dominant
E) homozygous dominant or heterozygous

Question 21

What is the probability of rolling two six- sided dice and obtaining two 4's?

Question 22

Mendel performed numerous controlled genetic crosses to obtain strains that consistently produced a single phenotype without variation. What are these strains that consistently produce the same phenotype called?

Question 23

Huntington's disease is an autosomal dominant trait. Given the pedigree below, if individual IV- 4 has three children with a normal woman, what is probability that they would have at least one child with the disorder?

A) 1/8
B) 0
C) 1/2
D) 3/8
E) 7/8

Question 24

The genes responsible for some of the traits that Mendel observed have been recently identified and have helped in determining how molecular variation produces morphologic variation in pea plants. Allelic variation in the Sbe1 gene, which produces starch- branching enzyme 1, is responsible for which trait in peas?

A) axial and terminal flower position
B) yellow and green pea color
C) smooth and wrinkled pea shape
D) purple and white flowers
E) tall and short plant height

Question 25

What simple type of cross that investigates the inheritance of only one trait could be used to illustrate Mendel's law of segregation?

Question 26

What is the probability of rolling two six- sided dice and obtaining at least one 3?

Question 27

The law of independent assortment predicts that crossing of dihybrid F1 plants to one another would produce nine genotypes in a _ ratio among F2 progeny.

Question 28

What is the probability of rolling two six- sided dice and obtaining an odd number on at least one die?

Question 29

A cross between a short pea plant and a tall pea plant results in a 1:1 genotypic AND phenotypic ratio in the offspring. What are the genotypes of the parent plants?

Question 30

In mice, black coat color is dominant to white coat color. In the pedigree below, mice with a black coat are represented by darkened symbols, and those with white coats are shown as open symbols. What could you conclude regarding the genotype of mouse II- 3 if a testcross resulted in 5 mice with black coat color and 6 mice with white coat color?

A) The genotype of II- 3 must be homozygous dominant.
B) The genotype of II- 3 could be homozygous dominant or heterozygous.
C) The genotype of II- 3 must be homozygous recessive.
D) The genotype of II- 3 could be homozygous recessive or heterozygous.
E) The genotype of II- 3 must be heterozygous.

Question 31

In a test cross, a pure- breeding plant is crossed with a plant suspected to be heterozygous (Aa). What is the genotype of the pure- breeding plant?

Question 32

In the accompanying figure, the chance that individual IV- 7 is a heterozygous carrier is _ .

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

Question 33

In some of Mendel's experiments, a cross in which one plant provides the pollen and another with the same genotype provides the egg is followed be another cross in which the first plant provides the egg while the second provides the pollen. During his experiments, these _ crosses produced identical results.

Question 34

What is the probability of rolling one six- sided die and obtaining a 1 or a 2?

Question 35

Huntington's disease is an autosomal dominant trait. Given the pedigree below, if individual IV- 2 has three children with a normal man, what is probability that exactly two of the three children would have the disorder?

A) 3/8
B) 7/8
C) 0
D) 1/2
E) 1/8

Question 36

In the accompanying figure, the chance that individual III- 5 is a heterozygous carrier is _ .

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

Question 37

In the accompanying figure, if individual IV- 7 has three children with individual IV- 2 what is the probability (to the nearest hundredth) that they would have exactly two affected offspring?

A) 0.44
B) 0.67
C) 0.17
D) 0.02
E) 0.07

Question 38

In 1997, a gene called Le was discovered by two research groups led by David Martin and Diane Lester. Allelic variation in the Le gene, which controls elongation of the plant stem between branches, is responsible for which trait in peas?

A) yellow and green pod color
B) inflated and constricted pod shape
C) axial and terminal flower position
D) tall and short plant height
E) purple and white flowers

Question 39

What is the probability of rolling one six- sided die and obtaining any number but 6?

Question 40

Why did Mendel cut off the nascent anthers during the process of artificial cross- fertilization?

Question 41

The pedigree suggests which mode of inheritance for an allele on chromosome 15?

Question 42

In a cross between individuals who are both heterozygous (carriers) for a recessive disease, such as albinism, you would like to determine the risk of one or more children inheriting the recessive phenotype. probability can be used to calculate the probability of a particular combination of events that each have two alternative outcomes?

Question 43

If an affected individual is born to parents who are unaffected, what is the likely mode of inheritance?

Question 44

Geneticists must be able to compare the outcomes they obtain in their experiments to the outcomes that might be expected to occur. Which test would they use to confirm that the difference between observed and expected outcomes could be attributed to chance?

Question 45

A geneticist is investigating the inheritance of two autosomal recessive genes in mice, one for obesity (LEP) and another for autism (oprm1). The table below provides the number of offspring observed, for each phenotype, when dihybrid mice are testcrossed: Fill in the table above and determine:
a. the chi- square (ç²) value (to the nearest hundredth) for the chance hypothesis that the two genes assort independently
b. the degrees of freedom
c. whether or not you would reject your chance hypothesis that the two genes assort independently, based on approximate P value, and the justification for why

Question 46

Describe the blending theory of heredity and how Mendel's results help to reject this theory.

Question 47

One key to Mendel's success was choosing to observe traits, which exhibit one of two possible phenotypes.

Question 48

A geneticist is investigating the inheritance of two autosomal recessive genes in mice, one for obesity (LEP) and for autism (oprm1). The table below provides the number of offspring observed, for each phenotype, when dihy mice are crossed: Fill in the table above and determine:
a. the chi- square (ç²) value (to the nearest hundredth) for the chance hypothesis that the two genes assort independently
b. the degrees of freedom
c. whether or not you would reject your chance hypothesis that the two genes assort independently, based on y approximate P value, and the justification for why

Question 49

What are Mendel's first and second laws of inheritance, and what do they state?

Question 50

You have self- fertilized a plant with round seeds that is heterozygous, and you want to determine what proportion of the offspring will be dominant and true breeding. probability can be used to calculate the probability of obtaining a particular outcome when specific information about that outcome modifies the probability calculation?

Question 51

In Guinea pigs, short hair (S) is dominant over long hair (s), rough coat (R) is dominant over smooth coat (r), and hair (B) is dominant over white hair (b). List all the different possible gametes that can be produced by each of th individuals below.
a. SSRRbb
b. ssRrBB
c. SsRrbb
d. SsRrBb

Question 52

Tim and Mary are planning to start a familiy. While neither of them have cystic fibrosis, a rare autosomal recessi disease, they are concerned that their children could have the disease since Tim's father, John, AND Mary's broth Ralph both have the disease.
a. Draw a pedigree of the inheritance of the cystic fibrosis allele in this family.
b. On your pedigree, indicate any individuals that must be carriers.
c. What is the probability that Tim will be a carrier for the disease allele?
d. What is the probability that Mary will be a carrier for the disease allele?
e. What is the probability that Tim and Mary will have a child with the disease?

Question 53

A ratio of 9:3:3:1 is expected among the F2 progeny of a dihybrid cross as a result of
of alleles at two loci.

Question 54

The P value is dependent on the number of , which is equal to the number of independent variables in an experiment.

Question 55

Describe the traits that make Pisum sativum an ideal organism for genetic studies.