Question 1

If one pair of genes could cause some flowers to have red petals or yellow petals and could also determine the strength of the stem, this would be an example of

Accepted Answer

A)  polygenic inheritance. 
B)  pleiotropy. 
C)  recessiveness. 
D)  hybrid.

Question 2

When a gene has the ability to influence several different aspects of the phenotype of an organism, this is referred to as

Accepted Answer

A)  polygenic inheritance. 
B)  pleiotropy. 
C)  multiple alleles. 
D)  lack of dominance.

Question 3

A condition in which a diploid organism has different allelic forms of a particular gene is the definition of

Accepted Answer

A)  homozygous. 
B)  phenotype. 
C)  genotype. 
D)  heterozygous.

Question 4

In humans, the genes for blood type A and B show lack of dominance to one another and both dominate O. Two type O people would be able to have

Accepted Answer

A)  1 O: 1 A: 1 B: 1 AB type children. 
B)  only O type children. 
C)  1 O: 1 A type children. 
D)  only AB type children.

Question 5

If the parents of a child have the following genotypes [Bb * Bb], what is the probability that they will have a child with the genotype [BB]?

Accepted Answer

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

Question 6

Which of the following does NOT express one of Mendel's laws?

Accepted Answer

A)  When two different alleles are present for a given trait, the expression of one will mask the expression of the other. 
B)  Alleles separate during the formation of sex cells. 
C)  During the formation of sex cells, members of one gene pair separate from one another independently of members of other gene pairs. 
D)  Genes located on the same chromosome have a greater tendency of being inherited together than do genes located on different chromosomes.

Question 7

In the cross AaBb * AaBb, ____ of the offspring will express ___.

Accepted Answer

A)  1/16; both dominant traits 
B)  3/16; one dominant and one recessive trait 
C)  6/16; one dominant and one recessive trait 
D)  3/16; both recessive traits

Question 8

A gene that can be masked by another gene is called

Accepted Answer

A)  pleiotropy. 
B)  dominant. 
C)  incompletely dominant. 
D)  recessive.

Question 9

In humans, normal vision dominates color-deficiency, and both are X-linked. (The genes are located on the X chromosome.) A color-deficient male marries a woman who is heterozygous for normal vision. If they have a boy, the chance that he will be color-deficient is

Accepted Answer

A)  100%. 
B)  0%. 
C)  75%. 
D)  50%.

Question 10

In fruit flies, long wing (L) is dominant, vestigial wing (l) is recessive, gray body (G) is dominant, ebony body (g) is recessive. Two fruit flies were mated that were long-winged with gray bodies. The genotype of these two parental flies is LlGg * LlGg. What proportion of the offspring flies would have long wings and gray bodies?

Accepted Answer

A)  All offspring would be long-winged with gray bodies. 
B)  Nine-sixteenths of the offspring would be long-winged with gray bodies. 
C)  Three-fourths of the offspring would be long-winged with gray bodies. 
D)  Seven-sixteenths of the offspring would be long-winged with gray bodies.

Question 11

"She is a carrier of the cystic fibrosis trait." This statement acknowledges that this person

Accepted Answer

A)  is homozygous for the trait. 
B)  is heterozygous for the trait. 
C)  may be trisomic. 
D)  has two recessive alleles.

Question 12

"Two out of three times, they will pass on the trait." This is a statement of

Accepted Answer

A)  probability. 
B)  possibility. 
C)  certainty. 
D)  confusion.

Question 13

A male has a genotype RrTt. What is the probability of his producing Rt sperm cells?

Accepted Answer

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

Question 14

In a cross between two blue Andalusian chickens, 25% of the offspring produced were white, 25% where black, and 50% were blue Andalusian like the parents. Color in these chickens is most likely inherited by

Accepted Answer

A)  multiple alleles. 
B)  polygenic. 
C)  pleiotropy. 
D)  incomplete dominance.

Question 15

In snapdragons, FR = red flowers and FW = white flowers. Plants heterozygous for flower color have pink flowers. A cross between two pink-flowered plants will produce ____ red-flowered plants.

Accepted Answer

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

Question 16

"We are only going to trace this one trait from one generation to another." This statement would indicate that

Accepted Answer

A)  the researcher is not sure of how this trait is inherited. 
B)  they will be developing a monohybrid (single factor) line. 
C)  multiple alleles are involved here. 
D)  a double-factor cross has been made.

Question 17

Nearly two dozen different alleles for the same gene can determine eye color in fruit flies. This is an example of

Accepted Answer

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

Question 18

In pea plants, smooth seeds (S) are dominant over wrinkled seeds (S). A cross is made between a wrinkled-seed variety and a heterozygous smooth-seed variety. The chance of getting offspring homozygous for smooth seeds is

Accepted Answer

A)  0/4. 
B)  1/4. 
C)  1/2. 
D)  1/1.

Question 19

Geneticists use this term when explaining how genetic information is converted into physical features of a cell or organism.

Accepted Answer

A)  gene expression 
B)  gene replication 
C)  genetic mutation 
D)  genetic transcription

Question 20

"She is a carrier of the cystic fibrosis trait." This statement acknowledges that this person is

Accepted Answer

A)  homozygous for the trait. 
B)  heterozygous for the trait. 
C)  trisomic. 
D)  carrying two recessive alleles.

Exam 10: Patterns of Inheritance