Chapter 9 MCQS Flashcards

Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early
embryo with how many cells?
A) 4
B) 8
C) 16
D) 32
E) 64

If there are 20 chromatids in a cell, how many centromeres are there?
A) 10
B) 20
C) 30
D) 40
E) 80

In eukaryotic cells, chromosomes are composed of DNA
A) and RNA.
B) only.
C) and proteins.
D) and phospholipids.

What is produced if a cell divides by mitosis but does not undergo cytokinesis?
A) two cells, one cell containing two nuclei and a second cell without a nucleus
B) two cells, each cell with half of the genetic material of the parent cell
C) one cell with one nucleus containing half of the genetic material of the parent cell
D) one cell with two nuclei, each identical to the nucleus of the parent cell

Humans produce skin cells by mitosis and gametes by meiosis. The nuclei of skin cells
produced by mitosis will have
A) half as much DNA as the nuclei of gametes produced by meiosis.
B) the same amount of DNA as the nuclei of gametes produced by meiosis.
C) twice as much DNA as the nuclei of gametes produced by meiosis.
D) four times as much DNA as the nuclei of gametes produced by meiosis.

Compared to most prokaryotic cells, eukaryotic cells typically have
A) more DNA molecules and larger genomes.
B) the same number of DNA molecules but larger genomes.
C) the same number of DNA molecules and similarly sized genomes.
D) fewer DNA molecules but larger genomes.
E) fewer DNA molecules and smaller genomes.

At which phase are centrioles beginning to move apart in animal cells?
A) telophase
B) anaphase
C) prometaphase
D) metaphase
E) prophase

If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each
daughter cell following cytokinesis?
A) 10
B) 20
C) 30
D) 40
E) 80

Where do the microtubules of the spindle originate during mitosis in animal cells?
A) centromere
B) centrosome
C) centriole
D) chromatid
E) kinetochore

Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol
disrupts microtubule formation by binding to microtubules and accelerating their assembly from
the protein precursor tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect
A) the formation of the mitotic spindle.
B) anaphase.
C) formation of the centrioles.
D) chromatid assembly.
E) the S phase of the cell cycle.

Which of the following are primarily responsible for cytokinesis in plant cells but not in
animal cells?
A) kinetochores
B) Golgi-derived vesicles
C) actin and myosin
D) centrioles and centromeres
E) tubulin and dynein

Movement of the chromosomes during anaphase would be most affected by a drug that
prevents
A) nuclear envelope breakdown.
B) cell wall formation.
C) elongation of microtubules.
D) shortening of microtubules.
E) formation of a cleavage furrow.

Measurements of the amount of DNA per nucleus were taken on a large number of cells
from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In
which stage of the cell cycle did the nucleus contain 6 picograms of DNA?
A) G0
B) G1
C) S
D) G2
E) M

A group of cells is assayed for DNA content immediately following mitosis and is found to
have an average of 8 picograms of DNA per nucleus. How many picograms would be found at
the end of S and the end of G2?
A) 8; 8
B) 8; 16
C) 16; 8
D) 16; 16
E) 12; 16

The beginning of anaphase is indicated by which of the following?
A) Chromatids lose their kinetochores.
B) Cohesin attaches the sister chromatids to each other.
C) Cohesin is cleaved enzymatically.
D) Kinetochores attach to the metaphase plate.
E) Spindle microtubules begin to polymerize.

During which phase of mitosis do the chromatids become chromosomes?
A) telophase
B) anaphase
C) prophase
D) metaphase
E) cytokinesis

What is a cleavage furrow?
A) a ring of vesicles forming a cell plate
B) the separation of divided prokaryotes
C) a groove in the plasma membrane between daughter nuclei
D) the metaphase plate where chromosomes attach to the spindle
E) the space that is created between two chromatids during anaphase

Using which of the following techniques would enable your lab group to distinguish between
a cell in G2 and a cell from the same organism in G1?
A) fluorescence microscopy
B) electron microscopy
C) spectrophotometry
D) radioactive-labeled nucleotides
E) labeled kinetochore proteins

You have the technology necessary to measure each of the following in a sample of animal
cells: chlorophylls, organelle density, picograms of DNA, cell wall components, and enzymatic
activity. Which would you expect to increase significantly from M to G1?
A) organelle density and enzymatic activity
B) cell wall components and DNA
C) chlorophyll and cell walls
D) organelle density and cell walls
E) chlorophyll and DNA

A plant-derived protein known as colchicine can be used to poison cells by blocking the
formation of the spindle. Which of the following would result if colchicine is added to a sample
of cells in G2?
A) The cells would immediately die.
B) The cells would be unable to begin M and stay in G2.
C) The chromosomes would coil and shorten but have no spindle to which to attach.
D) The chromosomes would segregate but in a disorderly pattern.
E) Each resultant daughter cell would also be unable to form a spindle.

Motor proteins require which of the following to function in the movement of chromosomes
toward the poles of the mitotic spindle?
A) intact centromeres
B) a microtubule-organizing center
C) a kinetochore attached to the metaphase plate
D) ATP as an energy source
E) synthesis of cohesin

When a cell is in late anaphase of mitosis, which of the following will we see?
A) a clear area in the center of the cell
B) chromosomes clustered at the poles
C) individual chromatids beginning to separate from one another
D) chromosomes clustered tightly at the center
E) breaking down of the nuclear envelope

Cells from advanced malignant tumors often have very abnormal chromosomes as well as an abnormal number of chromosomes. What might explain the association between malignant
tumors and chromosomal abnormalities?
A) Cancer cells are no longer density dependent.
B) Cancer cells are no longer anchorage dependent.
C) Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities.
D) Chromosomally abnormal cells still have normal metabolism.
E) Transformation introduces new chromosomes into cells.

Which is the first checkpoint in the cell cycle where a cell will be caused to exit the cycle if
this point is not passed?
A) G0
B) G1
C) G2
D) S
E) previous M

Which of the following is released by platelets in the vicinity of an injury?
A) PDGF
B) MPF
C) protein kinase
D) cyclin
E) Cdk

Which of the following is a protein synthesized at specific times during the cell cycle that
associates with a kinase to form a catalytically active complex?
A) PDGF
B) MPF
C) protein kinase
D) cyclin
E) Cdk