Mitosis and the Cell Cycle:
1) In a diploid cell with 5 chromosome pairs (2n = 10), how many centromeres will be found in a
nucleus at G2 of the cell division cycle?
A) 5
B) 10
C) 20
D) 40
2) Scientists isolate cells in various phases of the cell cycle. They isolate a group of cells that
have 1 1/2 times more DNA than G1 phase cells. What is the most likely part of the cell cycle
from which these cells were isolated?
A) between the G1 and S phases in the cell cycle
B) in the G2 phase of the cell cycle
C) in the M phase of the cell cycle
D) in the S phase of the cell cycle
3) Metaphase is characterized by ________.
A) alignment of chromosomes on the equator of the cell
B) separation of the centromeres
C) cytokinesis
D) separation of sister chromatids
4) Certain cell types normally have several nuclei per cell. How could such multinucleated cells
be explained?
A) The cell underwent repeated cytokinesis but no mitosis.
B) The cell underwent repeated mitosis with simultaneous cytokinesis.
C) The cell underwent repeated mitosis, but cytokinesis did not occur.
D) The cell had multiple S phases before it entered mitosis.
5) If there are 40 centromeres in a cell at anaphase of mitosis, how many chromosomes will be
found in each daughter cell following cytokinesis?
A) 10
B) 20
C) 40
D) 80
6) During which phase of mitosis do the chromatids become chromosomes?
A) telophase
B) anaphase
C) prophase
D) metaphase
7) Use the figure to answer the question below.
The unlettered circle at the top of the figure shows a diploid nucleus with four chromosomes that
have not yet replicated. There are two pairs of homologous chromosomes, one long and the other
short. One haploid set is black, and the other is gray. The circles labeled A to E show various
combinations of these chromosomes.
What is the correct chromosomal condition at prometaphase of mitosis?
A) B
B) C
C) D
D) E
8) Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and,
therefore, can be assayed to track their incorporation. In a set of experiments, a student-faculty
research team used labeled T nucleotides to study the incorporation of labeled nucleotides into a
culture of lymphocytes. They found that the lymphocytes incorporated the labeled nucleotide at a
significantly higher level after a pathogen was introduced into the culture. What might they
conclude from this observation?
A) The pathogen consumed radiolabeled nucleotides.
B) Infection causes lymphocytes to divide more rapidly.
C) Infection causes lymphocytes to increase in size.
D) Infection causes lymphocyte cultures to skip some parts of the cell cycle.
Meiosis
For the next three questions reference the diagram above:
9) What is the key difference between the outcomes of mitosis and meiosis as shown in the
diagram?
A. Mitosis produces four non-identical haploid cells, while meiosis produces two identical
diploid cells.
B. Mitosis produces two genetically identical diploid cells, while meiosis produces four
genetically diverse haploid cells.
C. Mitosis produces four identical haploid cells, while meiosis produces four identical diploid
cells.
D. Both mitosis and meiosis produce the same number and type of cells.
10) Based on the diagram, why are the products of meiosis genetically distinct, while the
products of mitosis are not?
A. Meiosis involves two rounds of replication, while mitosis involves one.
B. Independent assortment and crossing over create novel allele combinations in meiosis, while
mitosis conserves the parental genome.
C. DNA replication is error-prone in meiosis but error-free in mitosis.
D. Mitosis occurs in somatic cells, so recombination is suppressed, while meiosis occurs in germ
cells, so recombination is required.
11) The diagram shows fertilization restoring diploidy by combining egg and sperm genomes. If
a sperm cell carried a mutation generated during meiosis II, how would that mutation be
represented in the zygote?
A. It would appear in only one chromatid of one homolog, making the zygote heterozygous for
the mutation.
B. It would appear in both chromatids of a homolog, making the zygote homozygous for the
mutation.
C. It would appear in all chromatids of both homologs, affecting every copy of that chromosome.
D. It would be corrected during fertilization because egg and sperm undergo mismatch repair
before fusion.
12) Which of the following statements is true of a species that has a chromosome number of 2n =
16?
A) The species is diploid with 32 chromosomes per cell.
B) The species has 16 sets of chromosomes per cell.
C) Each diploid cell has eight homologous pairs of chromosomes.
D) A gamete from this species has four chromosomes.
13) In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these
pairs, such as pair 14, which of the following do the two chromosomes of the pair have in
common?
A) length and position of the centromere only
B) length, centromere position, and staining pattern only
C) length, centromere position, staining pattern, and traits coded for by their genes
D) They have nothing in common except that they are X-shaped.
14) Which of the following statements describes a major difference between meiosis II and
mitosis in a diploid animal?
A) Homologous chromosomes align on the metaphase plate in meiosis II.
B) Sister chromatids separate in mitosis, and homologous chromosomes separate in meiosis II.
C) Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.
D) Crossing over of chromosomes takes place in meiosis II.
15) How many unique gametes could be produced through independent assortment by an
individual with the genotype RrSsTTUuVVWW?
A) 4
B) 8
C) 16
D) 64
16) A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for
tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete
from this organism?
A) Hh
B) HhTt
C) T
D) HT
17) Gray seed color in peas is dominant to white. Assume that Mendel conducted a series of
experiments where plants with gray seeds were crossed among themselves, and the following
progeny were produced: 302 gray and 98 white. What is the most probable genotype of each
parent?
A) GG × gg
B) Gg × Gg
C) GG × Gg
D) gg × Gg
18) Which of the following calculations require the use of the addition rule of probability?
A) Calculate the probability of black offspring from the cross AaBb × AaBb, where B is the
symbol for black.
B) Calculate the probability of children with both cystic fibrosis and polydactyly when parents
are each heterozygous for both genes.
C) Calculate the probability of each of four children having cystic fibrosis if the parents are both
heterozygous.
D) Calculate the probability of a child having either sickle-cell anemia or cystic fibrosis if
parents are each heterozygous for both.
19) A man has extra digits (six fingers on each hand and six toes on each foot). His wife and
their daughter have the normal number of digits (five fingers on each hand and five toes on each
foot.) Having extra digits is a dominant trait. The couple's second child has extra digits. What is
the probability that their next (third) child will have extra digits?
A) 1/2
B) 1/16
C) 1/8
D) 3/4
20) The following question refers to the pedigree chart in the figure for a family, some of whose
members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or
circle.
What is the probability that individual III-1 is Ww?
A) 3/4
B) 1/4
C) 2/4
D) 1
21) The figure shows the pedigree for a family. Dark-shaded symbols represent individuals with
one of the two major types of colon cancer. Numbers under the symbols are the individual's age
at the time of diagnosis. Males are represented by squares, females by circles.
From this pedigree, this trait seems to be inherited ________.
A) from mothers
B) as an autosomal recessive
C) as a result of epistasis
D) as an autosomal dominant