Question 1

The observable outward manifestation of the genes of an individual is referred to as its

Accepted Answer

A)  blueprint.
B)  genotype.
C)  phenotype.
D)  genetic map. C

Question 2

what proportion of the long-eared offspring will be homozygous for the long-eared allele?

Accepted Answer

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

Question 3

Let P = purple flowers and p = white, and T = tall plants and t = dwarf.What are the genotypes of the gametes that are produced by a plant that is heterozygous for both traits?

Accepted Answer

A)  PpTt only
B)  PT and pt
C)  P, p, T, and t
D)  PT, Pt, pT, and pt D

Question 4

The first detailed and quantitative studies on inheritance were carried out by an Austrian monk named _____.

Accepted Answer

A)  Mendel
B)  Darwin
C)  Mendeleev
D)  Benedict

Question 5

Height is a trait that shows continuous variation in humans.In pea plants, on the other hand, the tall allele is dominant over the short allele and there are no intermediate heights.What is the best explanation for this difference?

Accepted Answer

A)  The alleles that control height in pea plants are epistatic.
B)  The alleles that control height in pea plants are pleiotropic.
C)  The alleles that control height in humans are pleiotropic.
D)  Height is a polygenic trait in humans.

Question 6

The genotypic ratio produced in the last cross is most likely

Accepted Answer

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

Question 7

A cross where we follow the inheritance of 2 pairs of alleles is called

Accepted Answer

A)  homozygous.
B)  monohybrid.
C)  dihybrid.
D)  heterozygous.

Question 8

A person who has lost a large amount of blood but is still alive is found in a wrecked automobile under a highway bridge.Several people are helping the paramedics load the victim into the ambulance.After the ambulance has departed for the hospital, you overhear the following conversation from the persons who helped the paramedics."I am certain that when that guy gets to the hospital, they will transfuse him with any blood that they have in the blood bank since he has lost so much blood." The other person says, "Yeah, I bet you're right!" Having had a biology course, you know which blood could be safely given to anyone.Select it below.

Accepted Answer

A)  A
B)  B
C)  AB
D)  O

Question 9

Let Y = yellow and y = green, and R = round and r = wrinkled.You cross YYRR peas with yyrr peas.All of the F1 individuals are yellow and round with a genotype of YyRr.You then perform an F2 cross and get the expected 9:3:3:1 phenotypic ratio.What proportion of the F2 plants are expected to be heterozygous for both traits?

Accepted Answer

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

Question 10

The observable expression of the genes present in an organism is called its

Accepted Answer

A)  phenotype.
B)  genotype.
C)  pedigree.
D)  karyotype.

Question 11

The phenotypic ratio for the F1 generation that results from a testcross between a homozygous individual and a heterozygous individual is

Accepted Answer

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

Question 12

In Mendel's experiments on seed color in pea plants, when a dominant yellow seed-bearing plant was crossed with a recessive green seed-bearing plant, what was the approximate phenotypic ratio among the F2 generation?

Accepted Answer

A)  1 yellow: 3 green
B)  1 yellow: 1 green
C)  3 yellow: 1 green
D)  all yellow

Question 13

ABO blood group determination is an example of

Accepted Answer

A)  epistasis.
B)  incomplete dominance.
C)  polygenic inheritance.
D)  multiple alleles.

Question 14

The most-likely explanation for this inheritance pattern is that the secretor trait is

Accepted Answer

A)  incompletely dominant.
B)  recessive.
C)  dominant.
D)  co-dominant.

Question 15

In white tigers, the absence of fur pigmentation is caused by a recessive allele that also causes the tigers to be cross-eyed.If two tigers heterozygous for this allele mate, what do you expect to see among the offspring?

Accepted Answer

A)  1/4 will be both white and cross-eyed, 3/4 will be orange with normal eyes.
B)  1/4 will be white with normal eyes, 1/4 will be white and cross-eyed, 1/4 will be orange with normal eyes, and 1/4 will be orange and cross-eyed.
C)  1/16 will be white and cross-eyed, 15/16 will be orange with normal eyes.
D)  1/3 will be both white and cross-eyed, 2/3 will be orange with normal eyes.

Question 16

Mendel performed reciprocal crosses in which he used pollen from a white-flowered plant to fertilize a purple-flowered plant and pollen from a purple-flowered plant to fertilize a white-flowered plant.What did these reciprocal crosses demonstrate?

Accepted Answer

A)  The female gamete made a larger genetic contribution to the offspring than the male gamete.
B)  Each parent made an equal genetic contribution to the offspring.
C)  Flower color is a sex-linked trait.
D)  The traits of flower color and sex assort independently.

Question 17

Alternate forms of the same gene are called

Accepted Answer

A)  homologues.
B)  genotypes.
C)  cofactors.
D)  alleles.

Question 18

In humans, the sickle-cell trait is caused by a single defective allele, but sickle-cell disease only occurs in individuals that are homozygous for the sickle-cell allele.A man and woman each carry the trait, but do not have sickle-cell disease.What is the probability that their first two children will both have sickle-cell disease?

Accepted Answer

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

Question 19

Sometimes, when Mendel crossed two pea plants with each other, he obtained a phenotypic ratio of 3:1 purple-flowered pea plants to white-flowered pea plants.These results are consistent with which set of parents?

Accepted Answer

A)  homozygous purple pea plant and homozygous white pea plant
B)  heterozygous purple pea plant and homozygous white pea plant
C)  heterozygous purple pea plant and homozygous purple pea plant
D)  heterozygous purple pea plant and heterozygous purple pea plant

Question 20

The ______ of an organism refers to the alleles that are present.

Accepted Answer

A)  genotype
B)  karyotype
C)  pedigree
D)  phenotype

Exam 12: Patterns of Inheritance