Ch. 12
1. What is the correct order for the phases of the cell cycle?
A. S, G2, M, and G1
B. G2, M, S, and G1
C. M, S, G2, and G1
D. None of the above
2. Many cancers are due to the failure of cells to properly regulate which checkpoint
during the cell cycle
A. G1
B. G2
C. Metaphase
D. None of the above
If DNA is physically damaged, the p53 protein pauses the cell cycle or initiates
apoptosiscell death. P53 is a tumor suppressor. If there is a failure in the G1
checkpoint, p53 will not initiate apoptosis.
3. The mitotic spindle fibers originate from what structure?
A. Kinetochore
B. Centrosomes
C. Centromeres
D. None of the above
4. The activity of Mitosis-promoting factor (MPF) is cyclical, its activity increases
A. During anaphase
B. In the late G2 phase
C. In the S phase
D. None of the above
Cyclin binds Cyclin-dependent kinase (Cdk) to form MPF.
Cdk catalyzes phosphorylation (the addition of a phosphate group) of other proteins
to start M phase
5. The longest part of the cell cycle is
A. Mitosis
B. Interphase
C. Cytokinesis
D. None of the above
Chapter 13:
6. Crossing over occurs when
A. During Meiosis I between sister chromatids on the same chromosome
B. During Meiosis I between chromatids of homologous chromosomes
C. During Meiosis II between chromatids of homologous chromosomes
D. During Mitosis during prophase
In prophase I
7. The nuclei of the 2 daughter cells produced from meiosis will be
A. Diploid following Meiosis II
B. Haploid following Meiosis I
C. Haploid following Meiosis II
D. None of the above
**Meiosis I and Meiosis Ii both produce two haploid cells.
8. Which of the following is support for the purifying selection hypothesis?
A. Sexual reproduction is more efficient than asexual reproduction
B. Asexual reproduction involves the crossing over in meiosis and the fusion
of gametes
C. Asexual reproduction results in unique daughter cells compared to
parental cells
D. Sexually reproducing parents can produce offspring that are unique and
lack deleterious alleles
9. Fragaria is a plant genus that is octaploid, meaning that it has 8 pairs of
chromosomes. How many sister chromatids do the nuclei of these plants have
during the G1 phase and the G2 phase respectively?
A. 8:16
B. 16:16
C. 16:32
D. 32:64
In G1 there are 2 sister chromatids per chromosome, and the DNA replicates in the S
phase before G2 producing 2 pairs of 2 sister chromosomes in the nucleus
10. If a cell has a diploid number of 6 before meiosis, how many chromosomes will
be in each of the four daughter cells if one pair of chromosomes experience
nondisjunction during meiosis I?
A. Two cells will have 6 chromosomes, two cells will have none
B. Two cells will have 4 chromosomes, two cells will have 2 chromosomes
C. Two cells will have 5 chromosomes, two cells will have 1 chromosome
D. All four cells will have 3 chromosomes
During meiosis I the 3 homologous pairs will line up and one pair of the homologs
will not separate. This results in 4 chromosomes in one cell and 2 chromosomes in
another cell. After meiosis II there will be a resulting 2 cells with 4 chromosomes
and 2 cells with 2 chromosomes.
Chapter 14:
11. What is the frequency of the phenotype in the F2 generation of a homozygous
dominant parent and a homozygous recessive parent for the allele ‘R’.?
A. 1:1:1:1
B. 1:2:1
C. 3:1
D. 1
RR x rr -parental generation-  Rr -F1 generation-  RR: 2 Rr: rr –F2 generationRR and the 2 Rr are the dominant phenotype, and rr is the recessive phenotype.
12. If the results of a testcross results in one half dominant phenotype and one half
recessive phenotype, what is a possible genotype of the unknown parent
A. RR
B. Rr
C. rr
D. All of the above
A testcross crossing a homozygous recessive (rr) parent by a parent that has a
dominant phenotype but could be RR or Rr. In this case because half of the progeny
have the recessive phenotype, the unknown parent must have been Rr.
13. Which of the following statements about an X-linked recessive disease is true?
A. All male offspring from an affected female and an unaffected male would
have the disease
X[r]X[r] by X[R]Y  X[r] Y recessive male
B. All female offspring from an affected female and an unaffected male
would have the disease
X[r]X[r] by X[R]Y  X[R]X[r] dominant female
C. No offspring from an affected female and an unaffected male would have
the disease
D. None of the above
The female will always pass on her recessive allele, in men that will be their only X,
in women they will have a dominant allele from their father’s X chromosome.
14. If two linked genes on the X chromosome in a single cell, separate into four
haploid daughter cells, how many genotypes are possible in the daughter cells?
A. 2
B. 4
C. 8
D. None of the above
The possibilities are limited from 4 due to crossing over to 2 because the linked
genes will stay with each other.
Blood type is an example of multiple allelism, if a blood type A with genotype IAi
crosses with a blood type B with genotype IBIB what blood types could the progeny
be?
A. Blood type A and B
B. Blood type B and AB
C. Blood type AB only
D. None of the above
A
A: I i
B: IBIB
Progeny: IAIB (AB), IBi (B)