2025/2026
TEST BANK FOR AN
INTRODUCTION TO
GENETIC ANALYSIS
ELEVENTH EDITION
ANTHONY JF GRIFFITHS
chapter 2 questions and
answers 2025/2026
[Author name]
,Chapter 2
Single-Gene Inheritance
MULTIPLE-CHOICE QUESTIONS
Sections 2.1. and 2.2. (Single gene inheritance, The chromosomal basis of single-gene
inheritance patterns)
1. If a plant of genotype A/a is selfed, and numerous offspring are scored, what proportion of the
progeny is expected to have homozygous genotypes?
A) 0
B) 25%
C) 50%
D) 75%
E) 100%
Anṣwer C
2. What is the maximum number of heterozygous genotypes that could be produced by
monohybrid self?
A) 1
B) 2
C) 3
D) 4
E) 6
Anṣwer A
3. A plant is heterozygous at three loci. How many different gamete genotypes can it
theoretically produce with respect to these three loci?
A) 2
B) 3
C) 4
D) 8
E) 16
Anṣwer D
4. In mountain rabbits, the EL-1 gene is located on chromosome 3. Four alleles of this gene have
been identified in the population. With respect to EL-1, what is the maximum number of
genotypes in the progeny of a single cross between two mountain rabbits?
A) 1
B) 2
C) 3
D) 4
, E) 6
Anṣwer D
5. A wild-type strain of haploid yeast is crossed to a mutant strain with phenotype d. What
phenotypic ratios will be observed in the progeny?
A) all wild type
B) 75% wild type and 25% mutant (d)
C) 50% wild type and 50% mutant (d)
D) 25% wild type and 75% mutant (d)
E) all mutant (d)
Anṣwer C
Section 2.3. (The molecular basis of Mendelian inheritance patterns)
6. Mice (Mus musculus) have 40 chromosomes per diploid cell (2n = 40). How many double-
stranded DNA molecules and how many chromosomes are there in a mouse cell that is in the G2
stage of the cell cycle?
A) 40 DNA molecules and 20 chromosomes
B) 40 DNA molecules and 40 chromosomes
C) 40 DNA molecules and 80 chromosomes
D) 80 DNA molecules and 40 chromosomes
E) 80 DNA molecules and 80 chromosomes
Anṣwer D
7. A mutation occurs in a germ cell of a pure-breeding, wild-type male mouse prior to DNA
replication. The mutation is not corrected, and the cell undergoes DNA replication and a normal
meiosis producing four gametes. How many of these gametes will carry the mutation?
A) 1
B) 2
C) 3
D) 4
E) It is impossible to predict.
Anṣwer B
8. What is the mechanism that ensures Mendel’s first law of segregation?
A) formation of chiasmata
B) formation of the kinetochore
C) pairing of homologous chromosomes
D) segregation of homologous chromosomes during meiosis I
E) segregation of sister chromatids during meiosis II
TEST BANK FOR AN
INTRODUCTION TO
GENETIC ANALYSIS
ELEVENTH EDITION
ANTHONY JF GRIFFITHS
chapter 2 questions and
answers 2025/2026
[Author name]
,Chapter 2
Single-Gene Inheritance
MULTIPLE-CHOICE QUESTIONS
Sections 2.1. and 2.2. (Single gene inheritance, The chromosomal basis of single-gene
inheritance patterns)
1. If a plant of genotype A/a is selfed, and numerous offspring are scored, what proportion of the
progeny is expected to have homozygous genotypes?
A) 0
B) 25%
C) 50%
D) 75%
E) 100%
Anṣwer C
2. What is the maximum number of heterozygous genotypes that could be produced by
monohybrid self?
A) 1
B) 2
C) 3
D) 4
E) 6
Anṣwer A
3. A plant is heterozygous at three loci. How many different gamete genotypes can it
theoretically produce with respect to these three loci?
A) 2
B) 3
C) 4
D) 8
E) 16
Anṣwer D
4. In mountain rabbits, the EL-1 gene is located on chromosome 3. Four alleles of this gene have
been identified in the population. With respect to EL-1, what is the maximum number of
genotypes in the progeny of a single cross between two mountain rabbits?
A) 1
B) 2
C) 3
D) 4
, E) 6
Anṣwer D
5. A wild-type strain of haploid yeast is crossed to a mutant strain with phenotype d. What
phenotypic ratios will be observed in the progeny?
A) all wild type
B) 75% wild type and 25% mutant (d)
C) 50% wild type and 50% mutant (d)
D) 25% wild type and 75% mutant (d)
E) all mutant (d)
Anṣwer C
Section 2.3. (The molecular basis of Mendelian inheritance patterns)
6. Mice (Mus musculus) have 40 chromosomes per diploid cell (2n = 40). How many double-
stranded DNA molecules and how many chromosomes are there in a mouse cell that is in the G2
stage of the cell cycle?
A) 40 DNA molecules and 20 chromosomes
B) 40 DNA molecules and 40 chromosomes
C) 40 DNA molecules and 80 chromosomes
D) 80 DNA molecules and 40 chromosomes
E) 80 DNA molecules and 80 chromosomes
Anṣwer D
7. A mutation occurs in a germ cell of a pure-breeding, wild-type male mouse prior to DNA
replication. The mutation is not corrected, and the cell undergoes DNA replication and a normal
meiosis producing four gametes. How many of these gametes will carry the mutation?
A) 1
B) 2
C) 3
D) 4
E) It is impossible to predict.
Anṣwer B
8. What is the mechanism that ensures Mendel’s first law of segregation?
A) formation of chiasmata
B) formation of the kinetochore
C) pairing of homologous chromosomes
D) segregation of homologous chromosomes during meiosis I
E) segregation of sister chromatids during meiosis II
