Campbell Biology Genetics 200 Multiple
Choice Questions with Verified Answers
and Detailed Rationales Complete Study
Guide for A+ Exam Success
SECTION 1: MEIOSIS AND SEXUAL LIFE CYCLES (Questions 1–30)
Question 1
Which of the following best describes a genome?
A) A single chromosome
B) The complete set of an organism's genes
C) A pair of homologous chromosomes
D) The protein-coding regions of DNA only
ANS: B
Rationale: A genome is the complete set of genes or genetic material present in a cell or
organism. It includes both coding and non-coding sequences. A single chromosome is only part
of the genome; homologous chromosomes are pairs; and protein-coding regions represent only
a fraction of the genome .
Question 2
How many chromosomes does a human somatic cell contain?
A) 23
B) 46
C) 92
D) 22
ANS: B
,Rationale: Human somatic (body) cells are diploid (2n), containing 46 chromosomes—23 pairs
of homologous chromosomes. Gametes contain 23 chromosomes (haploid) .
Question 3
What is the term for the two chromosomes that make up a matched pair in a diploid cell?
A) Sister chromatids
B) Homologous chromosomes
C) Autosomes
D) Sex chromosomes
ANS: B
Rationale: Homologous chromosomes are a pair of chromosomes of the same length,
centromere position, and staining pattern that carry genes for the same traits at corresponding
loci—one inherited from each parent. Sister chromatids are identical copies joined at the
centromere .
Question 4
During which phase of meiosis do homologous chromosomes separate?
A) Metaphase I
B) Anaphase I
C) Anaphase II
D) Telophase II
ANS: B
Rationale: Homologous chromosomes separate during anaphase I of meiosis, reducing the
chromosome number from diploid to haploid. Sister chromatids separate during anaphase II .
Question 5
What is the main difference between meiosis I and meiosis II?
A) Meiosis I separates sister chromatids; meiosis II separates homologous chromosomes
B) Meiosis I separates homologous chromosomes; meiosis II separates sister chromatids
,C) Both separate homologous chromosomes
D) Both separate sister chromatids
ANS: B
Rationale: Meiosis I is the reductional division where homologous chromosomes separate.
Meiosis II is the equational division where sister chromatids separate, similar to mitosis .
Question 6
During which stage of meiosis does crossing over occur?
A) Prophase I
B) Metaphase I
C) Anaphase I
D) Prophase II
ANS: A
Rationale: Crossing over—the exchange of genetic material between non-sister chromatids of
homologous chromosomes—occurs during prophase I at the chiasmata. This is a major source
of genetic variation .
Question 7
What is the result of independent assortment during meiosis?
A) Identical daughter cells
B) Random distribution of maternal and paternal chromosomes into gametes
C) Duplication of chromosomes
D) Formation of identical gametes
ANS: B
Rationale: Independent assortment refers to the random orientation of homologous
chromosome pairs at metaphase I, resulting in different combinations of maternal and paternal
chromosomes in gametes. This creates genetic variation. Human gametes can have over 8
million different combinations .
Question 8
, What type of cell division produces gametes?
A) Mitosis
B) Meiosis
C) Binary fission
D) Budding
ANS: B
Rationale: Meiosis produces gametes (sperm and egg cells) with half the chromosome number
(haploid), allowing for sexual reproduction and genetic variation upon fertilization .
Question 9
Which of the following contributes to genetic variation during meiosis?
A) Crossing over only
B) Independent assortment only
C) Random fertilization only
D) All of the above
ANS: D
Rationale: Genetic variation during sexual reproduction results from three main sources:
crossing over (prophase I), independent assortment (metaphase I), and random fertilization
(union of gametes). All three contribute to offspring diversity .
Question 10
How many daughter cells are produced at the end of meiosis II?
A) 1
B) 2
C) 4
D) 8
ANS: C
Rationale: Meiosis involves two consecutive divisions (meiosis I and meiosis II) resulting in four
haploid daughter cells, each genetically distinct from the parent cell and from each other .
Choice Questions with Verified Answers
and Detailed Rationales Complete Study
Guide for A+ Exam Success
SECTION 1: MEIOSIS AND SEXUAL LIFE CYCLES (Questions 1–30)
Question 1
Which of the following best describes a genome?
A) A single chromosome
B) The complete set of an organism's genes
C) A pair of homologous chromosomes
D) The protein-coding regions of DNA only
ANS: B
Rationale: A genome is the complete set of genes or genetic material present in a cell or
organism. It includes both coding and non-coding sequences. A single chromosome is only part
of the genome; homologous chromosomes are pairs; and protein-coding regions represent only
a fraction of the genome .
Question 2
How many chromosomes does a human somatic cell contain?
A) 23
B) 46
C) 92
D) 22
ANS: B
,Rationale: Human somatic (body) cells are diploid (2n), containing 46 chromosomes—23 pairs
of homologous chromosomes. Gametes contain 23 chromosomes (haploid) .
Question 3
What is the term for the two chromosomes that make up a matched pair in a diploid cell?
A) Sister chromatids
B) Homologous chromosomes
C) Autosomes
D) Sex chromosomes
ANS: B
Rationale: Homologous chromosomes are a pair of chromosomes of the same length,
centromere position, and staining pattern that carry genes for the same traits at corresponding
loci—one inherited from each parent. Sister chromatids are identical copies joined at the
centromere .
Question 4
During which phase of meiosis do homologous chromosomes separate?
A) Metaphase I
B) Anaphase I
C) Anaphase II
D) Telophase II
ANS: B
Rationale: Homologous chromosomes separate during anaphase I of meiosis, reducing the
chromosome number from diploid to haploid. Sister chromatids separate during anaphase II .
Question 5
What is the main difference between meiosis I and meiosis II?
A) Meiosis I separates sister chromatids; meiosis II separates homologous chromosomes
B) Meiosis I separates homologous chromosomes; meiosis II separates sister chromatids
,C) Both separate homologous chromosomes
D) Both separate sister chromatids
ANS: B
Rationale: Meiosis I is the reductional division where homologous chromosomes separate.
Meiosis II is the equational division where sister chromatids separate, similar to mitosis .
Question 6
During which stage of meiosis does crossing over occur?
A) Prophase I
B) Metaphase I
C) Anaphase I
D) Prophase II
ANS: A
Rationale: Crossing over—the exchange of genetic material between non-sister chromatids of
homologous chromosomes—occurs during prophase I at the chiasmata. This is a major source
of genetic variation .
Question 7
What is the result of independent assortment during meiosis?
A) Identical daughter cells
B) Random distribution of maternal and paternal chromosomes into gametes
C) Duplication of chromosomes
D) Formation of identical gametes
ANS: B
Rationale: Independent assortment refers to the random orientation of homologous
chromosome pairs at metaphase I, resulting in different combinations of maternal and paternal
chromosomes in gametes. This creates genetic variation. Human gametes can have over 8
million different combinations .
Question 8
, What type of cell division produces gametes?
A) Mitosis
B) Meiosis
C) Binary fission
D) Budding
ANS: B
Rationale: Meiosis produces gametes (sperm and egg cells) with half the chromosome number
(haploid), allowing for sexual reproduction and genetic variation upon fertilization .
Question 9
Which of the following contributes to genetic variation during meiosis?
A) Crossing over only
B) Independent assortment only
C) Random fertilization only
D) All of the above
ANS: D
Rationale: Genetic variation during sexual reproduction results from three main sources:
crossing over (prophase I), independent assortment (metaphase I), and random fertilization
(union of gametes). All three contribute to offspring diversity .
Question 10
How many daughter cells are produced at the end of meiosis II?
A) 1
B) 2
C) 4
D) 8
ANS: C
Rationale: Meiosis involves two consecutive divisions (meiosis I and meiosis II) resulting in four
haploid daughter cells, each genetically distinct from the parent cell and from each other .
