Chapter 2
Cellular Reproduction and Model Genetic Organisms
1. Which of the following substances is unique to prokaryotic cell walls ( i.e., is not found in eukaryotic cell
walls)?
a. proteins
b. glycogen
c. glycolipids
d. polysaccharides
e. peptidoglycan
Ans: e
Link to: Cells and Chromosomes
Difficulty: Medium
2. Which of the following is the most important difference between eukaryotes and prokaryotes?
a. Eukaryotes have a cell wall, prokaryotes do not.
b. Prokaryotes divide by binary fission, eukaryotes do not.
c. Eukaryotes have a true nucleus, prokaryotes do not.
d. Eukaryotes are multicellular, prokaryotes are unicellular.
e. Eukaryotes have a cell membrane, prokaryotes do not.
Ans: c
Link to: Cells and Chromosomes
Difficulty: Easy
3. Which of the following functions is associated with the nucleolus?
a. DNA synthesis
b. RNA synthesis
c. cell division
d. meiosis
e. mitosis
Ans: b
Link to: Cells and Chromosomes
Difficulty: Easy
4. All of the following statements about subcellular organelles are true, except:
a. Rough ER is associated with protein synthesis.
b. Protein modifications occur in the mitochondria.
c. Lysosomes contain powerful digestive enzymes.
d. Enzymes contained in the peroxisomes use molecular oxygen for their action.
e. Chloroplasts are sites of photosynthesis.
Ans: b
Link to: Cells and Chromosomes
6
Chapter 2
Difficulty: Easy
5. The synthesis of the energy-rich molecule, ATP, takes place in which of the following organelles?
a. mitochondria
b. chloroplasts
c. thylakoids
d. peroxisomes
e. rough ER
Ans: a
Link to: Cells and Chromosomes
Difficulty: Easy
6. The Golgi complex is involved in all of the following functions, except:
a. ATP synthesis.
b. protein modification.
c. complex carbohydrate synthesis.
d. exocytosis.
e. protein storage.
Ans: a
Link to: Cells and Chromosomes
Difficulty: Easy
7. All of the following are different parts of a eukaryotic chromosome, except:
a. chromatid.
b. centrosome.
c. kinetochore.
d. telomere.
e. centromere.
Ans: b
Link to: Mitosis
Difficulty: Easy
8. During the eukaryotic cell cycle, replication of DNA takes place during which of the following phases?
a. G1
b. S
c. G2
d. M
e. all of the above
Ans: b
Link to: Mitosis
Difficulty: Easy
7
Chapter 2
9. Which of the following is the correct sequence of events in mitosis?
a. prophase, interphase, metaphase, telophase, and anaphase
b. interphase, cytokinesis, telophase, metaphase, and prophase
c. cytokinesis, telophase, interphase, metaphase, and prophase
d. prophase, anaphase, metaphase, telophase, and cytokinesis
e. interphase, prophase, metaphase, anaphase, and telophase
Ans: e
Link to: Mitosis
Difficulty: easy
10. The first indications of approaching mitosis in animal cells are observed in the cytoplasm of the cell
during which of the following phases?
a. prophase
b. anaphase
c. interphase
d. metaphase
e. telophase
Ans: c
Link to: Mitosis
Difficulty: Easy
11. Pairs of sister chromatids assume positions in the equatorial plate during which of the following phases
of mitosis?
a. prophase
b. anaphase
c. interphase
d. metaphase
e. telophase
Ans: d
Link to: Mitosis
Difficulty: Easy
12. Which of the following stages of meiosis is characterized by the formation of the synaptinemal
complex?
a. zygonema
b. leptonema
c. pachynema
d. diplonema
e. diakinesis
Ans: c
Link to: Meiosis
Difficulty: Hard
8
Chapter 2
13. The term chiasmata refers to which of the following phenomenon?
a. division of a bacteria cell into two equal daughter cells
b. asymmetric division of a bacterial cell into two daughter cells of unequal size
c. movement of chromosomes during mitosis
d. formation of microtubules during meiosis
e. crossing over of homologous chromosomes
Ans: e
Link to: Meiosis
Difficulty: easy
14. All of the following statements are true about meiosis, except:
a. During meiosis, chromosomal material replicates twice.
b. At the end of meiosis, each daughter cell is haploid.
c. During prophase I of meiosis, homologous chromosomes pair tightly to form tetrads.
d. Crossing over takes place only between nonsister chromatids.
e. The diplotene stage of meiosis can last several years in some animals.
Ans: a
Link to: Meiosis
Difficulty: easy
15. All of the following statements regarding meiosis are true, except:
a. The end result of meiosis is four haploid cells.
b. The most important consequence of meiosis is the production of genetic variation.
c. Meiosis only occurs in eukaryotes that reproduce sexually.
d. Behavior of chromosomes during meiosis is contradictory to Mendel's laws of independent assortment.
e. Exchange of genetic material takes place during the process of crossing over of chromosomes.
Ans: d
Link to: Meiosis
Difficulty: Easy
16. Which of the following is true about gamete formation in plants?
a. In plants, gametes rarely arise directly from meiosis.
b. The haploid products of meiosis in plants are called gametophytes.
c. A sporophyte is a haploid organism that develops from spores.
d. A gametophyte is a diploid organism that produces spores.
e. Plants do not have meiosis.
Ans: a
Link to: Meiosis
Difficulty: Hard
9
Chapter 2
17. Alternation of generations refers to
a. meiosis followed by mitosis in animal cells.
b. alternating G1 and G2 phases of the animal cell cycle.
c. alternating generation of haploid and diploid cells in sexually reproducing animals.
d. alternating sporophyte and gametophyte phases in plants.
e. oogenesis followed by spermatogenesis in hermaphrodite animals.
Ans: d
Link to: Meiosis
Difficulty: Hard
18. In the fruit fly, Drosophila melanogaster, the term imaginal discs refers to:
a. the first stage larva that feeds rapidly.
b. pre-adult clusters of determined tissue.
c. late larva stage that slows down and crawls to a dry place.
d. male and female reproductive structures.
e. the fruit fly fertilized egg.
Ans: b
Link to: Genetics in the Laboratory: An Introduction to Some Model Research Organisms
Difficulty: Medium
19. All of the following are true about the life cycle of the Arabidopsis, except:
a. Microgametogenesis yields two sperm cells.
b. Meiosis occurs during microsporogenesis and megagametogenesis.
c. Double fertilization occurs when sperm combine individually with the egg cell and the secondary
endosperm cell.
d. Pollen tube growth is induced by the pollen grain landing on the stigma.
e. Antipodal cells degenerate prior to pollination.
Ans: b
Link to: Genetics in the Laboratory: An Introduction to Some Model Research Organisms
Difficulty: Medium
20. Which of the following is not true about the life cycle of Neurospora crassa:?
a. Neurospora is a haploid filamentous fungus.
b. Neurospora reproduces sexually by the formation of conidia.
c. Asexual reproduction is the predominant mode of reproduction in Neurospora .
d. There are two mating types in the organism, A and a.
e. Ascospores are mature haploid spores.
Ans: b
Link to: Genetics in the Laboratory: An Introduction to Some Model Research Organisms
Difficulty: Medium
10
Chapter 2
21. The fundamental difference between eukaryotes and prokaryotes is that eukaryotes possess a nucleoid
while prokaryotes have a true nucleus.
Ans: F
Link to: Cells and Chromosomes
Difficulty: easy
22. Eukaryotic cells have membrane-bound proteins that are commonly complexed with carbohydrates.
Ans: T
Link to: Cells and Chromosomes
Difficulty: easy
23. One important difference between smooth and rough ER is that smooth ER is not associated with
ribosomes.
Ans: T
Link to: Cells and Chromosomes
Difficulty: easy
24. Mitochondria are subcellular organelles that probably originated from small prokaryotic cells that were
taken into a larger cell.
Ans: T
Link to: Cells and Chromosomes
Difficulty: easy
25. The mitochondrial outer membrane is folded into cristae and contains proteins involved in energy
transfer functions.
Ans: F
Link to: Cells and Chromosomes
Difficulty: easy
26. The structure that joins together the two sister chromatids after replication of chromosomes is called the
telomere.
Ans: F
Link to: Cells and Chromosomes
Difficulty: easy
11
Chapter 2
27. The phase of the eukaryotic cell cycle during which growth and increase in cell mass occurs following
cell division is called G2 phase.
Ans: F
Link to: Cells and Chromosomes
Difficulty: easy
28. The most important feature of mitosis is that both the parent and daughter cells are diploid.
Ans: T
Link to: Mitosis
Difficulty: easy
29. The centrosome is the primary microtubule organizing center of animal cells.
Ans: T
Link to: Mitosis
Difficulty: easy
30. The characteristic feature of the centrosome is that it is not duplicated during mitosis so that only one of
the daughter cells eventually receives it.
Ans: F
Link to: Mitosis
Difficulty: easy
31. Meiotic cell division is the process whereby the haploid chromosome number (n) is doubled to the
diploid (2n) state during gamete formation.
Ans: F
Link to: Meiosis
Difficulty: easy
32. The first stage of meiosis is called reductional division and the second stage is called equational
division.
Ans: T
Link to: Meiosis
Difficulty: Medium
33. Down syndrome is a genetic disorder that results from nondisjunction of chromosomes during mitosis.
12
Chapter 2
Ans: F
Link to: Meiosis
Difficulty: easy
34. One of the most important features of meiotic cell division is that it minimizes genetic variation among
sexually reproducing populations.
Ans: F
Link to: Meiosis
Difficulty: easy
15. Gametophytes are plants that produce haploid gametes that fuse to produce a diploid zygote.
Ans: T
Link to: Meiosis
Difficulty: Medium
35. What is the major difference between the reproductive cycles of Arabidopsis and animals?
Ans: The major difference between the reproductive cycles in plants and animals is the mode of gamete
formation. In animals, meiosis produces haploid cells that then mature into gametes. In plants, gametes
rarely arise directly from meiosis. Meiosis takes place in plants, but the resultant haploid products of
meiosis are called micro- and megaspores. Haploid microspores divide mitotically to produce two sperm
cells in a vegetative cell. By contrast, megaspores divide 3 times to yield eight different cells types of
which the haploid egg cell and the secondary endosperm cell arising by fusion of two haploid polar nuclei
are critical. Both cells are fertilized by one of the sperm cells during “double fertilization”. The embryo
comes from the fertilized egg cell whereas the fertilized endosperm cells provide nutrition for the growing
embryo.
Link to: Genetics in the Laboratory: An Introduction to Some Model Research Organisms
Difficulty: Medium
36. What is the basic difference between life cycles of Neurospora crassa and that of higher plants?
Ans: In Neurospora crassa and in most lower plants, the haploid condition is the dominant phase of the life
cycle. The diploid phase is fleeting and exists only after the fusion of two haploid spores, following which
meiosis produces the haploid state once again. As plants evolved and became more complicated, the diploid
phase of the life cycle became the dominant form with a diminishing of the haploid phase.
Link to: Genetics in the Laboratory: An Introduction to Some Model Research Organisms
Difficulty: Medium
37. What are the three main events of meiosis and what is its end result?
Ans: The three main events of meiosis are the pairing of homologous chromosomes, the exchange of
genetic material by crossing over, and the segregation of the members of a homologous pair of
13
Chapter 2
chromosomes into different daughter nuclei. Meiosis involves one round of DNA replication, followed by
two separate cell divisions, and results in the formation of four haploid cells.
Link to: Meiosis
Difficulty: Medium
38. How does meiosis give rise to genetic variation and what is the significance of this?
Ans: During meiosis chromosomes align randomly along the equatorial plate so that the gametes carry a
mixture of maternal and paternal chromosomes. Since there are 23 pairs of chromosomes in humans, for
each pair of chromosomes the probability that a gamete will get a maternal chromosome is 1/2, and for all
23 chromosomes, it is (1/2)23. In other words, there are 223 possible combinations of chromosomes. When
crossing over is factored in, the number of possible different genetic combinations becomes huge.
Therefore, meiosis is a mechanism for generating tremendous amounts of genetic variation in sexually
reproducing populations. This is very significant because populations with the greatest amount of genetic
variation tend to be the most successful in evolutionary terms.
Link to: Meiosis
Difficulty: Hard
39. Briefly describe the stages of spermatogenesis in humans.
Ans: Spermatogenesis begins in the human male at puberty and takes place in the testes in coiled tubes
called seminiferous tubules. The immature premeiotic germ cells are called spermatogonia. The
spermatogonia proliferate mitotically. At various points, a subset of the spermatogonia stop dividing,
enlarge, and differentiate into primary spermatocytes. Primary spermatocytes undergo meiosis I to produce
secondary spermatocytes and then meiosis II to produce four haploid spermatids. The spermatids
differentiate into mature spermatozoa, which pass into the lumen of the seminiferous tubule and then on to
the epididymis where they undergo further maturation. 
Link to: Meiosis
Difficulty: Medium
14