University of Michigan
3 MAXE · 171 OIB
★ ★
M College of Literature, Science & the Arts — Department of Biology
EST. 1817
ARTES · SCIENTIA · VERITAS
Bio-171 Exam 3
M E I O S I S · M E N D E L I A N G E N E T I CS · C H R O M O S O M A L I N H E R I TA N C E · C E L L CYC L E
INSTITUTION University of Michigan PROGRAM Bachelor of Science — Biology
COURSE CODE BIO 171 COURSE TITLE Introduction to Molecular &
Cellular Biology
ACADEMIC YEAR EXAM TITLE Bio-171 Exam 3
TOTAL QUESTIONS 52 Questions FORMAT Multiple Choice — Select the
Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question unless otherwise instructed.
▸ This examination covers meiosis, Mendelian genetics, chromosomal inheritance, the cell cycle, and
patterns of inheritance.
▸ Questions address crossing over, independent assortment, nondisjunction, epistasis, pleiotropy, and
related genetic concepts.
▸ Correct answers and explanatory rationales appear below each question for review purposes.
▸ All content reflects standard introductory biology curriculum for BIO 171 at the University of Michigan.
, SECTION I — MEIOSIS, GENETICS & CHROMOSOMAL
Questions 1 – 52
INHERITANCE
1. The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the
somatic (body) cells of a rabbit?
A. 11
B. 22
C. 44
D. 88
CORRECT ANSWER C — 44
RATIONALE The egg is a haploid gamete (n = 22). Somatic cells are diploid (2n), so they
contain twice the haploid number: 2 × 22 = 44 chromosomes. This relationship —
gametes are haploid, body cells are diploid — is a universal principle of sexual
reproduction in animals.
2. Which of the following processes has just occurred when chiasmata can first be viewed
under a microscope?
A. Meiosis II
B. Anaphase II
C. Prophase I
D. The separation of homologs
CORRECT ANSWER C — Prophase I
RATIONALE Chiasmata are the visible manifestations of crossing over — the physical points
where non-sister chromatids have exchanged genetic material. They become
visible during late prophase I (diplotene stage) when the synaptonemal complex
disassembles and homologous chromosomes begin to separate but remain
connected at crossover sites.
, 3. Asexual reproduction occurs during which of the following processes?
A. Meiosis
B. Mitosis
C. Fertilization
D. None of the above
CORRECT ANSWER B — Mitosis
RATIONALE Asexual reproduction produces genetically identical offspring through mitotic cell
division. Mitosis generates two diploid daughter cells that are clones of the
original. Meiosis produces haploid gametes for sexual reproduction. Fertilization
fuses gametes to restore diploidy.
4. Students in a biology lab isolated cells in various phases of the cell cycle. A population of
cells that have twice the DNA of G1 phase cells was most likely isolated from which of the
following parts of the cell cycle?
A. Between the G1 and S phase
B. In the G2 phase
C. Immediately after cytokinesis
D. At the beginning of the S phase
CORRECT ANSWER B — In the G2 phase
RATIONALE DNA content doubles during S phase. G1 cells have baseline DNA (2C). After S
phase, cells in G2 have twice that amount (4C) because each chromosome now
consists of two sister chromatids. Therefore, cells with twice the DNA of G1 are in
G2 or M phase.
3 MAXE · 171 OIB
★ ★
M College of Literature, Science & the Arts — Department of Biology
EST. 1817
ARTES · SCIENTIA · VERITAS
Bio-171 Exam 3
M E I O S I S · M E N D E L I A N G E N E T I CS · C H R O M O S O M A L I N H E R I TA N C E · C E L L CYC L E
INSTITUTION University of Michigan PROGRAM Bachelor of Science — Biology
COURSE CODE BIO 171 COURSE TITLE Introduction to Molecular &
Cellular Biology
ACADEMIC YEAR EXAM TITLE Bio-171 Exam 3
TOTAL QUESTIONS 52 Questions FORMAT Multiple Choice — Select the
Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question unless otherwise instructed.
▸ This examination covers meiosis, Mendelian genetics, chromosomal inheritance, the cell cycle, and
patterns of inheritance.
▸ Questions address crossing over, independent assortment, nondisjunction, epistasis, pleiotropy, and
related genetic concepts.
▸ Correct answers and explanatory rationales appear below each question for review purposes.
▸ All content reflects standard introductory biology curriculum for BIO 171 at the University of Michigan.
, SECTION I — MEIOSIS, GENETICS & CHROMOSOMAL
Questions 1 – 52
INHERITANCE
1. The egg (ovum) of a rabbit contains 22 chromosomes. How many chromosomes are in the
somatic (body) cells of a rabbit?
A. 11
B. 22
C. 44
D. 88
CORRECT ANSWER C — 44
RATIONALE The egg is a haploid gamete (n = 22). Somatic cells are diploid (2n), so they
contain twice the haploid number: 2 × 22 = 44 chromosomes. This relationship —
gametes are haploid, body cells are diploid — is a universal principle of sexual
reproduction in animals.
2. Which of the following processes has just occurred when chiasmata can first be viewed
under a microscope?
A. Meiosis II
B. Anaphase II
C. Prophase I
D. The separation of homologs
CORRECT ANSWER C — Prophase I
RATIONALE Chiasmata are the visible manifestations of crossing over — the physical points
where non-sister chromatids have exchanged genetic material. They become
visible during late prophase I (diplotene stage) when the synaptonemal complex
disassembles and homologous chromosomes begin to separate but remain
connected at crossover sites.
, 3. Asexual reproduction occurs during which of the following processes?
A. Meiosis
B. Mitosis
C. Fertilization
D. None of the above
CORRECT ANSWER B — Mitosis
RATIONALE Asexual reproduction produces genetically identical offspring through mitotic cell
division. Mitosis generates two diploid daughter cells that are clones of the
original. Meiosis produces haploid gametes for sexual reproduction. Fertilization
fuses gametes to restore diploidy.
4. Students in a biology lab isolated cells in various phases of the cell cycle. A population of
cells that have twice the DNA of G1 phase cells was most likely isolated from which of the
following parts of the cell cycle?
A. Between the G1 and S phase
B. In the G2 phase
C. Immediately after cytokinesis
D. At the beginning of the S phase
CORRECT ANSWER B — In the G2 phase
RATIONALE DNA content doubles during S phase. G1 cells have baseline DNA (2C). After S
phase, cells in G2 have twice that amount (4C) because each chromosome now
consists of two sister chromatids. Therefore, cells with twice the DNA of G1 are in
G2 or M phase.
