AP Bio 4.6-4.7 Test Bank

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

A) 10

Cells that are in a nondividing state are in which phase? A) G0 B) G2 C) G1 D) S E) M

A) G0

Nerve and muscle cells are in this phase: A) G0 B) G1 C) S D) G2 E) M

A) G0

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.

A) G1

G1 is represented by which number(s)? A) I and V B) II and IV C) III D) IV E) V

A) I and V

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

A) cells with more than one nucleus.

The centromere is a region in which A) chromatids remain attached to one another until anaphase. B) metaphase chromosomes become aligned at the metaphase plate. C) chromosomes are grouped during telophase. D) the nucleus is located prior to mitosis. E) new spindle microtubules form at either end.

A) chromatids remain attached to one another until anaphase.

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to A) disruption of mitotic spindle formation. B) inhibition of regulatory protein phosphorylation. C) suppression of cyclin production. D) myosin denaturation and inhibition of cleavage furrow formation. E) inhibition of DNA synthesis.

A) disruption of mitotic spindle formation.

Which term describes two centrosomes arranged at opposite poles of the cell? A) telophase B) anaphase C) prometaphase D) metaphase E) prophase

A)Anaphase

A group of researchers cultured yeast cells in a nutrient-rich environment and a nutrient-poor environment and observed the duration of the stages of their cell cycles. The results of their study are summarized in Table 1. The cell cycle of yeast cells grown in the nutrient-poor environment is approximately what percent of the cell cycle of yeast cells grown in the nutrient-rich environment? A.) 168 B.) 127 C.) 179 D.) 160

A.) 168

Glycogen synthetase kinase 3 beta is a protein kinase that has been implicated in many types of cancer. Depending on the cell type, the gene for glycogen synthetase kinase 3 beta (GSK3β) can act either as an oncogene or as a tumor suppressor. Which of the following best predicts how GSK3β mutations can lead to the development of cancer? A.) Cells with inactive GSK3β fail to trigger apoptosis. B.) Cells with inactive GSK3β fail to proceed past the G2/MG2/M checkpoint. C.) Cells with overactive GSK3β are more likely to repair DNA damage. D.) Cells with overactive GSK3β have longer cell cycles.

A.) Cells with inactive GSK3β fail to trigger apoptosis.

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

B) 20

The ʺrestriction pointʺ occurs here: A) G0 B) G1 C) S D) G2 E) M

B) G1

Which number represents DNA synthesis? A) I B) II C) III D) IV E) V

B) II

Which number represents the point in the cell cycle during which the chromosomes are replicated? A) I B) II C) III D) IV E) V

B) II

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei re-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.

B) a plant cell in the process of cytokinesis.

What is a chromatid? A) a chromosome in G1 of the cell cycle B) a replicate chromosome C) a chromosome found outside the nucleus D) a special region that holds two centromeres together E) another name for the chromosomes found in genetics

B) a replicate chromosome

Which term describes centromeres uncoupling, sister chromatids separating, and the two new chromosomes moving to opposite poles of the cell? A) telophase B) anaphase C) prometaphase D) metaphase E) prophase

B) anaphase

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

B) centrosome

If mammalian cells receive a go-ahead signal at the G1 checkpoint, they will A) move directly into telophase. B) complete the cycle and divide. C) exit the cycle and switch to a nondividing state. D) show a drop in MPF concentration. E) complete cytokinesis and form new cell walls.

B) complete the cycle and divide.

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

B) replication of the DNA

DNA is replicated at this time of the cell cycle: A) G0 B) G1 C) S D) G2 E) M

C) S

Researchers studying cell cycle regulation in budding yeast have observed that a mutation in the CDC15 gene causes cell cycle arrest in telophase when the yeast cells are incubated at an elevated temperature. Which of the following statements best predicts the effect of the cell cycle arrest on proliferating yeast cells? A) The yeast cells will transition out of G0 but will fail to complete G! phase B) The yeast cells will initate mitosis but will fail to complete G2 phase C) The yeast cells will replicate their chromosomes but will fail to complete cytokinesis D) The yeast cells will replicate their organelles but will fail to complete the S phase

C) The yeast cells will replicate their chromosomes but will fail to complete cytokinesis

Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants A) the spindles contain microfibrils in addition to microtubules, whereas animal spindles do not contain microfibrils. B) sister chromatids are identical, but they differ from one another in animals. C) a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage. D) chromosomes become attached to the spindle at prophase, whereas in animals chromosomes do not become attached until anaphase. E) spindle poles contain centrioles, whereas spindle poles in animals do not.

C) a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage.

Chromosomes first become visible during which phase of mitosis? A) prometaphase B) telophase C) prophase D) metaphase E) anaphase

C) prophase

Which of the following presents a correct interpretation of the changes in chromosome number depicted in Figure 1? A.) DNA replication occurs between metaphase and anaphase, doubling the number of chromosomes. Between telophase and cytokinesis, the cell divides in two, with each cell receiving half of the replicated chromosomes. B.) New chromosomes formed during prophase are doubled during anaphase and are recombined before cytokinesis. C.) Chromosomes enter metaphase containing two chromatids attached by a centromere. During anaphase, the chromatids are separated, each becoming a chromosome. Cytokinesis distributes the chromosomes into two separate cells. D.) At anaphase a cell contains two identical copies of each chromosome, but following telophase, one of the copies is broken down into nucleotides.

C.) Chromosomes enter metaphase containing two chromatids attached by a centromere. During anaphase, the chromatids are separated, each becoming a chromosome. Cytokinesis distributes the chromosomes into two separate cells.

Researchers performed an experiment to determine the effect of certain genetic mutations on mitosis in tropical fruit fly embryos. They determined the percentage of cells in each of four phases of mitosis as shown in Figure 1. Which of the following patterns is shown by the data? A.) Mutant 1 cells are more similar to mutant 3 cells than to wild-type cells. B.)In wild-type cells, the percent of cells in anaphase is twice the amount of those in telophase C.) In mutant 3 cells, more time is spent in prophase/prometaphase than in the later stages of mitosis. D.) The percent of mutant 2 cells in anaphase is higher than that of mutant 1 cells.

C.) In mutant 3 cells, more time is spent in prophase/prometaphase than in the later stages of mitosis.

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. Those cells would have __________ picograms at the end of the S phase and __________ picograms at the end of G2. A) 8; 8 B) 8; 16 C) 16; 8 D) 16; 16 E) 12; 16

D) 16; 16

A cell containing 92 chromatids at metaphase of mitosis would, at its completion, produce two nuclei each containing how many chromosomes? A) 12 B) 16 C) 23 D) 46 E) 92

D) 46

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 was the nucleus with 6 picograms of DNA? A) G0 B) G1 C) S D) G2 E) M

D) G2

In the figure above, mitosis is represented by which number? A) I B) II C) III D) IV E) V

D) IV

How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle? A) The daughter cells have half the amount of cytoplasm and half the amount of DNA. B) The daughter cells have half the number of chromosomes and half the amount of DNA. C) The daughter cells have the same number of chromosomes and half the amount of DNA. D) The daughter cells have the same number of chromosomes and the same amount of DNA. E) The daughter cells have the same number of chromosomes and twice the amount of DNA

D) The daughter cells have the same number of chromosomes and the same amount of DNA.

Which of the following conditions will most likely cause a normal body cell to become a cancer cell? A)The environment already contains cancer cells. B) The environment has an abundance of nutrients. C)The environment lacks signals that would otherwise tell the cell to stop dividing. D) The environment contains mutagens that induce mutations that affect cell-cycle regulator proteins.

D) The environment contains mutagens that induce mutations that affect cell-cycle regulator proteins

Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis? A) The chromosomes are ʺreeled inʺ by the contraction of spindle microtubules. B) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules. C) Non-kinetochore spindle fibers serve to push chromosomes in the direction of the poles. D) both A and B E) A, B, and C

D) both A and B

If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested? A) anaphase B) prophase C) telophase D) metaphase E) interphase

D) metaphase

Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis? A) telophase B) prophase C) anaphase D) metaphase E) prometaphase

D) metaphase

Movement of the chromosomes during anaphase would be most affected by a drug that A) reduces cyclin concentrations. B) increases cyclin concentrations. C) prevents elongation of microtubules. D) prevents shortening of microtubules. E) prevents attachment of the microtubules to the kinetochore

D) prevents shortening of microtubules.

Cytokinesis usually, but not always, follows mitosis. If a cell completed mitosis but not cytokinesis, the result would be a cell with A) a single large nucleus. B) high concentrations of actin and myosin. C) two abnormally small nuclei. D) two nuclei. E) two nuclei but with half the amount of DNA.

D) two nuclei.

What is the expected percent change in the DNA content of a typical eukaryotic cell as it progresses through the cell cycle from the start of the G1 phase to the end of the G2 phase? A.) -100% B.) -50% C.) +50% D.) +100%

D.) +100%

The relative amount of DNA in a cell at various stages of the cell cycle is shown in Figure 1. Which of the following best describes how the amount of DNA in the cell changes during M phase? A.) The amount of DNA doubles as the DNA is replicated. B.) The amount of DNA slightly increases as a result of new organelle synthesis. C.) The amount of DNA does not change while the cell grows. D.) The amount of DNA is halved as the cell divides into two daughter cells.

D.) The amount of DNA is halved as the cell divides into two daughter cells.

If a cell has 8 chromosomes at metaphase of mitosis, how many chromosomes will it have during anaphase? A) 1 B) 2 C) 4 D) 8 E) 16

E) 16

This is the shortest part of the cell cycle: A) G0 B) G1 C) S D) G2 E) M

E) M

A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation? A) The cell would prematurely enter anaphase. B) The cell would never leave metaphase. C) The cell would never enter metaphase. D) The cell would never enter prophase. E) The cell would undergo normal mitosis, but fail to enter the next G1 phase.

E) The cell would undergo normal mitosis, but fail to enter the next G1 phase.

The formation of a cell plate is beginning across the middle of a cell and nuclei are re-forming at opposite ends of the cell. What kind of cell is this? A) an animal cell in metaphase B) an animal cell in telophase C) an animal cell undergoing cytokinesis D) a plant cell in metaphase E) a plant cell undergoing cytokinesis

E) a plant cell undergoing cytokinesis

Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called A) ATPases. B) kinetochores. C) centrioles. D) proton pumps. E) cyclins.

E) cyclins

During which phases of mitosis are chromosomes composed of two chromatids? A) from interphase through anaphase B) from G1 of interphase through metaphase C) from metaphase through telophase D) from anaphase through telophase E) from G2 of interphase through metaphase

E) from G2 of interphase through metaphase

Which term describes centrioles beginning to move apart in animal cells? A) telophase B) anaphase C) prometaphase D) metaphase E) prophase

E) prophase