Question 1

A scientist has a pea plant that produces yellow seeds. Since yellow is dominant to green, she wants to determine if the plant is homozygous or heterozygous. In order to be certain that she will get conclusive results from a single cross, what is the BEST choice of plant to cross her pea plant with?
A. A green-seeded pea plant
B. A yellow-seeded pea plant
C. A pea plant that produces both green and yellow seeds
D. Itself

Accepted Answer

BESTA

Question 2

In humans, sickle-cell disease is due to a defect in a single gene and is inherited in an autosomal recessive manner. If 2 people without sickle-cell disease have a daughter who has this disease, what is the probability that their next child will be a boy with sickle-cell disease?

Accepted Answer

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

Question 3

Within the human body, different cells have different characteristics or phenotypes. For example, neurons look and behave very differently from hepatocytes (liver cells). How can this be explained considering that all cells within a person were derived from the same starting cell?

Accepted Answer

A)  Each cell type within a person must contain different genes. 
B)  Each cell type within a person must contain different proteins. 
C)  Each cell type within a person must contain different alleles for specific genes. 
D)  Each cell type within a person must undergo continuous variation. B

Question 4

In rabbits there is a dominant gene "T" for long ears and its recessive allele "t" for short ears. At another gene locus, there are alleles "B" for black coat and "W" for white coat. Neither allele is dominant and BW produces a gray coat. These two allele pairs assort independently. If a gray rabbit that is heterozygous at the gene locus controlling ear length is mated with a white rabbit that is also heterozygous at the gene locus controlling ear length, what proportion of the long-eared offspring will be homozygous for that trait?

Accepted Answer

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

Question 5

In watermelons, the gene for green color is dominant over its allele for striped color. At another gene locus, the gene for short shape is dominant over its allele for long shape. These two allele pairs assort independently. If a plant with long, striped fruit is crossed with a plant that is heterozygous for both of these traits, what percentage of the offspring do you expect will be short and green? ( Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5 )

Accepted Answer

The answer of In watermelons, the gene for green color...

Question 6

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 7

In rabbits, there is a dominant gene "T" for long ears and its recessive allele "t" for short ears. At another gene locus, there are alleles "B" for black coat and "W" for white coat. Neither allele is dominant and BW produces a gray coat. These two allele pairs assort independently. If a gray rabbit that is heterozygous at the gene locus controlling ear length is mated with a white rabbit that is also heterozygous at the gene locus controlling ear length, what is the probability that their first offspring will be gray with long ears?

Accepted Answer

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

Question 8

Knight followed up on attempts of English farmers to improve varieties of agriculture with his studies on garden peas. When he crossed two true-breeding varieties, he found all of the following: Check all that apply.

Accepted Answer

A)  All the F1 offspring had the dominant trait. 
B)  If both parents have the same trait, then all of their offspring will also have that trait. 
C)  Some F2 offspring had the dominant trait and some had the recessive trait. 
D)  Among the F2 offspring, more had the dominant trait and fewer had the recessive trait.

Question 9

Sometimes, when Mendel crossed two purple-flowered 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 of the following sets of parents?

Accepted Answer

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

Question 10

In white tigers, the absence of fur pigmentation is caused by a recessive allele. This allele 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. 
B)  1/4 will be white and 1/4 will be cross-eyed, but not necessarily the same 1/4 due to independent assortment. 
C)  1/16 will be white and 1/16 will be cross-eyed, but not necessarily the same 1/16 due to independent assortment. 
D)  1/16 will be both white and cross-eyed.

Exam 11: Patterns of Inheritance

In humans, sickle-cell disease is due to a defect in a single gene and is inherited in an autosomal recessive manner. If 2 people without sickle-cell disease have a daughter who has this disease, what is the probability that their next child will be a boy with sickle-cell disease?

Within the human body, different cells have different characteristics or phenotypes. For example, neurons look and behave very differently from hepatocytes (liver cells) . How can this be explained considering that all cells within a person were derived from the same starting cell?

Knight followed up on attempts of English farmers to improve varieties of agriculture with his studies on garden peas. When he crossed two true-breeding varieties, he found all of the following: Check all that apply.

Sometimes, when Mendel crossed two purple-flowered 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 of the following sets of parents?

In white tigers, the absence of fur pigmentation is caused by a recessive allele. This allele 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?