The best conclusion concerning delta is that the cells
A) contain no DNA.
B) contain no RNA.
C) contain only one chromosome that is very short.
D) are actually in the G0 phase.
E) divide in the G1 phase.

are actually in the G0 phase.

These protists are intermediate in what sense?
A) They reproduce by binary fission in their early stages of development and by mitosis when
they are mature.
B) They never coil up their chromosomes when they are dividing.
C) They use mitotic division but only have circular chromosomes.
D) They maintain a nuclear envelope during division.
E) None of them form spindles.

They maintain a nuclear envelope during division.

What is the most probable hypothesis about these intermediate forms of cell division?
A) They represent a form of cell reproduction that must have evolved completely separately from
those of other organisms.
B) They demonstrate that these species are not closely related to any of the other protists and
may well be a different kingdom.
C) They rely on totally different proteins for the processes they undergo.
D) They may be more closely related to plant forms that also have unusual mitosis.
E) They show some but not all of the evolutionary steps toward complete mitosis.

They show some but not all of the evolutionary steps toward complete mitosis.

Which of the following questions might be answered by such a method?
A) How many cells are produced by the culture per hour?
B) What is the length of the S phase of the cell cycle?
C) When is the S chromosome synthesized?
D) How many picograms of DNA are made per cell cycle?
E) When do spindle fibers attach to chromosomes?

What is the length of the S phase of the cell cycle?

The research team used the setup to study the incorporation of labeled nucleotides into a
culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a
significantly higher level after a pathogen was introduced into the culture. They concluded that
A) the presence of the pathogen made the experiment too contaminated to trust the results.
B) their tissue culture methods needed to be relearned.
C) infection causes lymphocytes to divide more rapidly.
D) infection causes cell cultures in general to reproduce more rapidly.
E) infection causes lymphocyte cultures to skip some parts of the cell cycle.

infection causes lymphocytes to divide more rapidly.

Through a microscope, you can see a cell plate beginning to develop across the middle of a
cell and nuclei forming on either side of the cell plate. This cell is most likely
A) an animal cell in the process of cytokinesis.
B) a plant cell in the process of cytokinesis.
C) an animal cell in the S phase of the cell cycle.
D) a bacterial cell dividing.
E) a plant cell in metaphase.

a plant cell in the process of cytokinesis.

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in
A) cells with more than one nucleus.
B) cells that are unusually small.
C) cells lacking nuclei.
D) destruction of chromosomes.
E) cell cycles lacking an S phase.

cells with more than one nucleus.

Which of the following does not occur during mitosis?
A) condensation of the chromosomes
B) replication of the DNA
C) separation of sister chromatids
D) spindle formation
E) separation of the spindle poles

replication of the DNA

A particular cell has half as much DNA as some other cells in a mitotically active tissue. The
cell in question is most likely in
A) G1.
B) G2.
C) prophase.
D) metaphase.
E) anaphase.

G1

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the
animal cell cycle would be most disrupted by cytochalasin B?
A) spindle formation
B) spindle attachment to kinetochores
C) DNA synthesis
D) cell elongation during anaphase
E) cleavage furrow formation and cytokinesis

cleavage furrow formation and cytokinesis