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CHAPTER 2
Concept check questions (in figure legends)
FIGURE 2.1
Concept check: Eukaryotic cells exhibit compartmentalization. What does this mean?
Answer: Compartmentalization means that cells have membrane-bound compartments.
FIGURE 2.2
Concept check: How do you think the end results would be affected if the cells were not
treated with a hypotonic solution?
Answer: The chromosomes would not be spread out very well, and would probably be
overlapping. It would be difficult to see individual chromosomes.
FIGURE 2.3
Concept check: How are homologs similar to each other and how are they different?
Answer: Homologs are similar in size, banding pattern, and carry the same types of
genes. However, the alleles of a given gene may be different.
FIGURE 2.4
Concept check: What is the function of FtsZ protein during binary fission?
Answer: FtsZ assembles into a ring at the future site of the septum and recruits other
proteins to this site that produce a cell wall between the two daughter cells.
FIGURE 2.5
Concept check: What is the difference between the G0 and G1 phases?
Answer: The G1 phase is a phase of the cell cycle when a cell may make the decision to
divide. By comparison, the G0 phase is a phase in which a cell is either not progressing
through the cell cycle or has made a decision to never divide again.
FIGURE 2.6
Concept check: What is the difference between homologs versus the chromatids within a
pair of sister chromatids?
Answer: Homologs are genetically similar; one is inherited from the mother and the other
from the father. By comparison, chromatids are the product of DNA replication. The
chromatids within a pair of sister chromatids are genetically identical.
FIGURE 2.7
Concept check: Where are the two ends of a kinetochore microtubule?
Answer: One end of a kinetochore microtubule is attached to a kinetochore on a
chromosome. The other end is within the centrosome.
FIGURE 2.8
Concept check: During which phase are sister chromatids separated and sent to opposite
poles?
Answer: Anaphase.
FIGURE 2.9
Concept check: What causes the cleavage furrow to ingress?
Answer: Ingression occurs because myosin motor proteins shorten the contractile ring,
which is formed from actin proteins.
FIGURE 2.10
Concept check: What is the end result of crossing over?
Answer: The end result of crossing over is that homologous chromosomes have
exchanged pieces.
FIGURE 2.11
Concept check: Where is the synaptonemal complex located? Is it between homologs or
is it between the chromatids within a pair of sister chromatids?
Answer: The synaptonemal complex is between homologs.
FIGURE 2.12
Concept check: How do the four cells at the end of meiosis differ from the original
mother cell?
Answer: The cells at the end of meiosis are haploid whereas the mother cell is diploid.
FIGURE 2.13
Concept check: How is this attachment of chromosomes to kinetochore microtubules
different from their attachment during metaphase of mitosis?
Answer: In mitosis, each pair of sister chromatids is attached to both poles, whereas in
metaphase of meiosis I, each pair of sister chromatids is attached to just one pole.
FIGURE 2.14
Concept check: What are polar bodies?
Answer: Polar bodies are small cells produced during oogenesis that degenerate.
FIGURE 2.15
Concept check: Are all of the cell nuclei in the embryo sac haploid or is just the egg
haploid?
Answer: All of the nuclei in the embryo sac are haploid. The central cell has two haploid
nuclei and all of the other cells, including the egg, have just one.