Question 1

A heterozygous tall, round-seed plant is crossed to a double-recessive, short, wrinkled-seed plant.What do we call the frequency at which short round seed and tall wrinkled seed are seen in the offspring?

Accepted Answer

A)  The mutation frequency 
B)  The meiotic frequency 
C)  The heterotic frequency 
D)  The allelic frequency 
E)  The recombinant frequency

Question 2

In cats, black coat (B) is codominant with yellow (b).The coat color gene is on the X chromosome.Calico cats, which have coats with black and yellow patches, are heterozygous for the coat color alleles.A calico female, Pickle, has a litter, whose characteristics are found in the table.  What is the genotype and phenotype of the father?

Accepted Answer

A)  XBY; yellow 
B)  XbY; yellow 
C)  XBY; black 
D)  XbY; black 
E)  XbY; calico

Question 3

If bacterial conjugation is allowed to take place for more than an hour, then two different genes (A and B) are transferred together.Even if conjugation occurs for only a few minutes, both A and B or neither of the genes is conjugated.It's only when conjugation takes place for only a few seconds that you see instances of only one of the genes being transferred.Most likely, genes A and B

Accepted Answer

A)  are involved in the same metabolic pathway. 
B)  are close together on the bacterial chromosome. 
C)  are far apart on the bacterial chromosome. 
D)  exhibit epistasis. 
E)  are codominant.

Question 4

Two genes with two alleles each are 30 centiMorgans (map units) apart.A double heterozygote whose parents were homozygous dominant and homozygous recessive is crossed to a double homozygous recessive.What frequency in the progeny will be double homozygotes?

Accepted Answer

A)  0 percent 
B)  15 percent 
C)  30 percent 
D)  35 percent 
E)  70 percent

Question 5

In pea plants, the allele R produces a red flower and is dominant to the white allele (r).A pea plant with red flowers is test crossed, and one-half of the resulting progeny have red flowers, whereas the other half have white flowers.Therefore, the genotype of the test-crossed parent was

Accepted Answer

A)  Rr. 
B)  RR. 
C)  rr. 
D)  either RR or Rr. 
E)  This cannot be answered without more information.

Question 6

Refer to the figure showing a family pedigree and recessive inheritance.Note the mother in generation I is a carrier of a rare recessive autosomal trait.  What is the probability an individual in generation IV will have the disease?

Accepted Answer

A)  0.03125 
B)  0.0625 
C)  0.125 
D)  0.375 
E)  0.5

Question 7

Refer to the figure showing a family pedigree in which several individuals develop a neurodegenerative disease late in life.  If individual A (in generation III) has children with an unaffected woman, what is the probability that their first child will be affected?

Accepted Answer

A)  0 percent 
B)  25 percent 
C)  33 percent 
D)  50 percent 
E)  100 percent

Question 8

The simple device that ensures that we consider all possible combinations of gametes when calculating expected genotype frequencies is known as a(n) _______ square.

Accepted Answer

The answer of The simple device that ensures that we...

Question 9

Jane is a better tennis player than Jack.If the probability that Jane will beat Jack in any given game is 0.7, what is the probability that they will each win one game if they play two games? (Note that there are two ways they can arrive at this outcome: Jane wins the first game or Jack wins the first game.)

Accepted Answer

A)  0.21 
B)  0.3 
C)  0.42 
D)  0.6 
E)  1

Question 10

In birds, males have two Z chromosomes, and females have a Z chromosome and a W chromosome.Suppose a gene that affected egg production was Z linked.Which value would be the best predictor of a female's egg production?

Accepted Answer

A)  Her mother's egg production 
B)  Her maternal grandmother's egg production 
C)  Her maternal aunt's egg production 
D)  Her paternal grandmother's egg production 
E)  There is no way to predict a female's egg production.

Question 11

A true-breeding strain of tall soybean plants is crossed with a true-breeding strain of short soybean plants.All the offspring are short.Thus, tall is a _______ trait.

Accepted Answer

A)  dominant 
B)  dihybrid 
C)  genotypic 
D)  monohybrid 
E)  recessive

Question 12

Refer to the table.In Drosophila, white (w), eosin (we), and wild-type red (w+) are multiple alleles at a single locus for eye color.This locus is on the X chromosome.A female that has eosin (pale orange) eyes is crossed with a male that has wild-type (red) eyes.All the female progeny are red-eyed; about half the male progeny have eosin eyes, and about half have white eyes.Assume the female has two X chromosomes and the male has one X and one Y.  What are the genotypes of the parents?

Accepted Answer

A)  wewe and wY 
B)  wew and wY 
C)  wew+ and wY 
D)  wew and w+Y 
E)  wewe and w+Y

Question 13

The t locus is involved in the production of tails in a mouse; tt individuals are without tails, whereas TT and Tt have tails.The l locus is involved in the color of tails: assuming that they have tails, individuals that are ll have light tails, whereas all others have dark tails.The two loci are on different chromosomes.In an F2 cross between TTLL and ttll individuals, what fraction will have light tails?

Accepted Answer

A)  1/16 
B)  3/16 
C)  1/4 
D)  1/2 
E)  9/16

Question 14

Which traits are most likely to be considered quantitative?

Accepted Answer

A)  Slow sprint speed versus fast sprint speed in lizards 
B)  Round versus wrinkled seeds 
C)  Red versus yellow flowers 
D)  Curly wings versus straight wings in flies 
E)  Human blood types

Question 15

Suppose you are a genetics counselor who is working with a 21-year-old pregnant woman who has just discovered that her father has Huntington's chorea, a rare dominant autosomal trait.This disease usually develops in middle age, so people carrying this trait do not find out they have this genetic disorder until midlife.What is the chance that she has Huntington's chorea?

Accepted Answer

A)  10% 
B)  25% 
C)  50% 
D)  75% 
E)  100%

Question 16

In garden peas, the allele for tall plants is dominant over the allele for short plants.A true-breeding tall plant is crossed with a short plant, and one of their offspring is test crossed.Out of 60 offspring resulting from the test cross, _______ should be short.

Accepted Answer

A)  0 
B)  about 15 
C)  about 30 
D)  about 45 
E)  about 60

Question 17

Suppose that in a certain population of lizards, the probability of the birth of a male is 0.6.Assume that the sex of each individual is independently determined.What is the probability that a clutch of three will have exactly two females? (Note that there are three ways to arrive at this outcome when calculating the probabilities of each egg's sex.)

Accepted Answer

A)  0.096 
B)  0.125 
C)  0.196 
D)  0.288 
E)  0.375

Question 18

Curly wing is recessive to straight wing in Drosophila.In a cross between true-breeding curly- and straight-winged parental flies, there are 480 flies in the F2 generation.How many F2 progeny should have curly wings?

Accepted Answer

A)  25 
B)  75 
C)  120 
D)  240 
E)  360

Question 19

Suppose a woman has blood type AB.From this, we can infer that

Accepted Answer

A)  her mother was also blood type AB. 
B)  her father was also blood type AB. 
C)  her father was type A, and her mother was type B. 
D)  her mother was type A, and her father was type B. 
E)  neither of her parents was type O.

Question 20

If big feet (B) in schmoos is dominant to small feet (b), the genotype of a big-footed schmoo with respect to the foot gene can

Accepted Answer

A)  only be bb. 
B)  only be BB. 
C)  either be Bb or BB. 
D)  either be bb or BB. 
E)  either be bb and Bb.

Exam 12: Inheritance, Genes, and Chromosomes

A heterozygous tall, round-seed plant is crossed to a double-recessive, short, wrinkled-seed plant.What do we call the frequency at which short round seed and tall wrinkled seed are seen in the offspring?

Two genes with two alleles each are 30 centiMorgans (map units) apart.A double heterozygote whose parents were homozygous dominant and homozygous recessive is crossed to a double homozygous recessive.What frequency in the progeny will be double homozygotes?

In pea plants, the allele R produces a red flower and is dominant to the white allele (r) .A pea plant with red flowers is test crossed, and one-half of the resulting progeny have red flowers, whereas the other half have white flowers.Therefore, the genotype of the test-crossed parent was

Refer to the figure showing a family pedigree and recessive inheritance.Note the mother in generation I is a carrier of a rare recessive autosomal trait. What is the probability an individual in generation IV will have the disease?

Refer to the figure showing a family pedigree in which several individuals develop a neurodegenerative disease late in life. If individual A (in generation III) has children with an unaffected woman, what is the probability that their first child will be affected?