Deck 2: Mitosis and Meiosis

Question 1

In which stage of the cell cycle is G0 located?

Answer 1

G1

Question 2

Homologous chromosomes can be matched by their similar structure and function within a nucleus. Which chromosomes making up a genome do not follow the same characteristics of homology?

Answer 2

sex -determining chromosomes

Question 3

During interphase of the cell cycle, _.

A) the nuclear membrane disappears
B) RNA replicates
C) sister chromatids move to opposite poles
D) DNA content essentially doubles
E) DNA recombines

Answer 3

D

Question 4

Name two cellular organelles, each having genetic material, that are involved in either photosynthesis or respiration.

Question 5

If a typical somatic cell has 64 chromosomes, how many chromosomes are expected in each gamete of that organism?

A) 128
B) 16
C) 8
D) 32
E) 64

Question 6

What is the name of the membranous structure that compartmentalizes the cytoplasm of eukaryotic organisms?

A) mitochondria
B) cytosol
C) ribosome
D) nucleoid
E) endoplasmic reticulum

Question 7

An interesting group of ants consists of several virtually identical, closely related species, with females having chromosome numbers of 18, 20, 32, 48, 60, 62, and 64. If one crossed a female of species (A) with 32 chromosomes and a male species (B) with 9 chromosomes (males are haploid, and each gamete contains the n complement), how many chromosomes would one expect in the body (somatic) cells of the female offspring?

A) 25
B) 4.5
C) 41
D) 9
E) 32

Question 8

The diploid chromosome number of an organism is usually represented as 2n. Humans have a diploid chromosome number of 46. What would be the expected haploid chromosome number in a human?

A) 92
B) 16
C) 23
D) 24
E) 12

Question 9

List four terms used to describe the normal morphologies, with respect to arm ratio, of eukaryotic chromosomes.

Question 10

For the purposes of this question, assume that a G1 somatic cell nucleus in a female Myrmecia pilosula contains 2 picograms of DNA. How much DNA would be expected in a metaphase I cell of a female?

A) 32 picograms
B) 16 picograms
C) 8 picograms
D) 4 picograms
E) Not enough information is provided to answer the question.

Question 11

In a healthy female, how many secondary oocytes would be expected to form from 100 primary oocytes? How many first polar bodies would be expected from 100 primary oocytes?

A) 200; 200
B) 50; 50
C) 100; 100
D) 100; 50
E) 200; 50

Question 12

Which type of cell structure is the nucleolus organizer (NOR) responsible for producing?

Question 13

What is the outcome of synapsis, a significant event in meiosis?

A) dyad formation
B) monad movement to opposite poles
C) chiasma segregation
D) side -by -side alignment of nonhomologous chromosomes
E) side -by -side alignment of homologous chromosomes

Question 14

Organized by the centrioles, what structures are important in the movement of chromosomes during cell division?

A) chloroplasts
B) centromeres
C) cell walls
D) mitochondria
E) spindle fibers

Question 15

The ant Myrmecia pilosula is found in Australia and is named bulldog because of its aggressive behavior. It is particularly interesting because it carries all its genetic information in a single pair of chromosomes. In other words, 2n = 2. (Males are haploid and have just one chromosome.) Which of the following figures would most likely represent a correct configuration of chromosomes in a metaphase I cell of a female?

A) A
B) B
C) C
D) D
E) E

Question 16

Living organisms are categorized into two major groups based on the presence or absence of a nucleus. What group is defined by the presence of a nucleus?

A) virus
B) mitochondrial organism
C) bacterium
D) prokaryotic organism
E) eukaryotic organism

Question 17

How many haploid sets of chromosomes are present in a diploid individual cell with a chromosome number of 46? 32?

Question 18

How many haploid sets of chromosomes are present in an individual cell that is tetraploid (4n)?

Question 19

In an organism with 52 chromosomes, how many bivalents would be expected to form during meiosis?

A) 26
B) 13
C) 52
D) 208
E) 104

Question 20

In a healthy male, how many sperm cells would be expected to form from (a) 400 primary spermatocytes? (b) 400 secondary spermatocytes?

A) (a) 1600; (b) 1600
B) (a) 1600; (b) 800
C) (a) 400; (b) 400
D) (a) 800; (b) 800
E) (a) 400; (b) 800

Question 21

If a typical G1 nucleus is 2n and contains 2C (two complements) of DNA, a prophase I cell is 2n and contains 4C of DNA.

Question 22

The house fly, Musca domestica, has a haploid chromosome number of 6. How many chromatids should be present in a diploid, somatic, metaphase cell?

Question 23

Trisomy 21 or Down syndrome occurs when there is a normal diploid chromosomal complement of 46 chromosomes plus one (extra) chromosome 21. Such individuals
therefore have 47 chromosomes. Assume that a mating occurs between a female with Down syndrome and a normal 46 -chromosome male. What proportion of the offspring would be expected to have Down syndrome? Justify your answer.

Question 24

Regarding the mitotic cell cycle, what is meant by a checkpoint?

Question 25

When cells withdraw from the continuous cell cycle and enter a "quiescent" phase, which stage are they said to be in?

Question 26

Drosophila melanogaster, the fruit fly, has a 2n chromosome number of 8. Assume that you are microscopically examining the mitotic and meiotic cells of this organism. You note that in the female, two chromosomal pairs are metacentric and two pairs are
acrocentric.
a() Draw the chromosomal configurations as you would expect to see them at the stages listed:
b() Given that the previously mentioned cells are from individuals heterozygous for two independently segregating, autosomal loci, plum eyes and curled wings, place
appropriate symbols (of your designation) on chromosomes in the drawings you made for part (a). Assume no crossing over, and there may be more than one correct answer in some cases.
c() Assuming that a somatic G2 nucleus from the individuals mentioned above
contains about 8.0 picograms of DNA, how much nuclear DNA would you expect in each of the cells mentioned in part (a)?

Question 27

After which meiotic stage (meiosis I or II) would one expect monads to be formed?

Question 28

List in order of occurrence the phases of mitosis.

Question 29

S phase is the part of interphase when DNA duplication takes place.

Question 30

The two terms reductional and equational generally refer to which stages of meiosis (I or II)?

Question 31

You may have heard through various media of an animal alleged to be the hybrid of a rabbit and a cat. Given that the cat (Felis domesticus) has a diploid chromosome number of 38 and a rabbit (Oryctolagus cuniculus) has a diploid chromosome number of 44,
what would be the expected chromosome number in the somatic tissues of this alleged hybrid?

Question 32

Name two evolutionarily significant benefits of meiosis that are not present in mitosis.

Question 33

The accompanying sketch depicts a cell from an organism in which 2n = 2 and each chromosome is metacentric.
a() Circle the correct stage for the cell in this sketch:
anaphase of mitosis anaphase of meiosis I
anaphase of meiosis II telophase of mitosis
b() Given that each G1 nucleus from this organism contains 16 picograms of DNA, how many picograms of chromosomal DNA would you expect in the cell shown here?

Question 34

The horse (Equus caballus) has 32 pairs of chromosomes, whereas the donkey (Equus asinus) has 31 pairs of chromosomes. How many chromosomes would be expected in the somatic tissue of a mule?

Question 35

List, in order of appearance, all the cell types expected to be formed during (a) spermatogenesis and (b) oogenesis.

Question 36

Normal diploid somatic (body) cells of the mosquito Culex pipiens contain six
chromosomes. Assign the symbols AmAp, BmBp, and CmCp to the three homologous chromosomal pairs. The "m" superscript indicates that the homolog is maternally
derived; the "p" indicates a paternally derived homolog. Assume that in the genus
Culex, the sex chromosomes are morphologically identical.
a() For each of the cell types given below, draw and label (with reference to the symbols defined above) an expected chromosomal configuration.
mitotic metaphase
metaphase of meiosis I metaphase of meiosis II
b() The stage at which "sister chromatids go to opposite poles" immediately follows which of the stages listed in (a)?
c() Assuming that all nuclear DNA is restricted to chromosomes and that the amount of nuclear DNA essentially doubles during the S phase of interphase, how much
nuclear DNA would be present in each cell listed in part (a)? Note: Assume that the G1 nucleus of a mosquito cell contains 3.0 × 10 -12 grams of DNA.
d() Given that the sex of Culex is determined by alleles of one gene -males
heterozygous, Mm, and females homozygous, mm-illustrate a labeled chromosomal
configuration (involving the symbols AmAp, BmBp, and CmCp and the M locus) in a primary spermatocyte at metaphase. Assume that the M locus is on the AmAp
chromosome and that crossing over has not occurred between the M locus and the centromere.

Question 37

Assume that the somatic cells of a male contain one pair of homologous chromosomes (e.g., AaAb) and an additional chromosome without a homolog (e.g., W). Which
chromosomal combinations would be expected in the meiotic products (spermatids) of a single primary spermatocyte? (There may be more than one answer.)

Question 38

What is meant by the term chiasma?

Question 39

There is about as much nuclear DNA in a primary spermatocyte as in (how
many) spermatids?

Question 40

Down syndrome, or trisomy 21, in humans is caused by an extra copy of the relatively small, acrocentric 21. Including only chromosome 21, the X chromosome (medium in size and somewhat metacentric) and the Y chromosome (small and acrocentric), draw one possible array of chromosomes in the four sperm cells produced by the complete meiosis of one primary spermatocyte. For the purposes of this question, assume that males with Down syndrome produce normal ratios of sperm cells. (More than one
answer is possible.)

Question 41

If a typical G1 nucleus contains 2C (two complements) of DNA, a gamete that is haploid (n) contains 1C of DNA.

Question 42

A bivalent at pachytene contains four chromatids.

Question 43

The centromere of a chromosome separates during anaphase.

Question 44

During meiosis, chromosome number reduction takes place in anaphase II.

Question 45

An organism with a haploid number of 10 will produce 1024 combinations of chromosomes at the end of meiosis.

Question 46

A chromosome may contain one or two chromatids in different phases of the mitotic or meiotic cell cycle.

Question 47

The meiotic cell cycle involves two cell divisions but only one DNA replication.

Question 48

An organism with a diploid chromosome number of 46 will produce 223 combinations of chromosomes at the end of meiosis.