Ch.12 module

Checkpoints in the cell cycle control system __________. A. regulate the cell cycle through a variety of stop and go signals B. ensure that a cell keeps dividing C. only stop cells from dividing D. only signal cells to undergo mitosis E. have no effect on the cell cycle F. stop cancer cells from dividing

A

During interphase, the genetic material of a typical eukaryotic cell is __________. A. dispersed in the nucleus as long strands of chromatin B. dispersed in the cytoplasm as long strands of chromatin C. condensed and the chromosomes are often visible under the light microscope D. attached to microtubule spindle fibers E. transported through the nuclear pores

A

One event occurring during prophase is __________. A. the beginning of the formation of a spindle apparatus B. the synthesis of a new nuclear envelope C. the alignment of chromosomes in a single plane D. cytokinesis E. division of the centromere

A

Which of the following events does not occur during interphase of the cell cycle? A. Separation of the sister chromatids B. Duplication of the chromosomes C. Growth of the cell D. Production of new mitochondria E. Protein production F. Production of the endoplasmic reticulum

A

Which of the following statements describes a cell that undergoes mitosis but not cytokinesis? A. The cell contains more than one nucleus. B. The cell has one nucleus. C. The cell does not contain a nucleus. D. The cell has undergone transformation and become a cancer cell. E. The cell has not proceeded through interphase. F. The cell dies.

A

A cell contains 40 chromatids at the beginning of mitosis. How many chromosomes will it contain at the completion of cytokinesis? A. 40 B. 20 C. 80 D. 10 E. 5 F. 160

B

How does the process of mitosis differ between most eukaryotes and other eukaryotes such as diatoms and dinoflagellates? A. The nuclear envelope remains intact in most eukaryotes but fragments in diatoms and dinoflagellates. B. The nuclear envelope fragments in most eukaryotes but remains intact in diatoms and dinoflagellates. C. Microtubules do not facilitate the movement of chromosomes in diatoms and dinoflagellates. D. The chromosomes are not duplicated prior to mitosis in diatoms and dinoflagellates. E. Sister chromatids are not separated during mitosis in diatoms and dinoflagellates. F. None of the listed responses is correct.

B

A cell biologist examined the DNA content of a cell from a fruit fly larva during the G1 phase and determined that it had 150 units of DNA. After measuring the DNA content of the same type of cell after the G2 phase, it was discovered that the cell had 300 units of DNA. How is this possible? A. The DNA was replicated during the G1 phase of interphase. B. The DNA was replicated during the G2 phase of interphase. C. The DNA was replicated during the S phase of interphase, which occurs between the two G phases. D. The DNA was replicated prior to interphase. E. The DNA was not replicated. This was the result of a mutation. F. The DNA was replicated after the G2 phase of interphase.

C

Chromatids are __________. A. held together by the centrioles B. found only in aberrant chromosomes C. identical copies of each other if they are part of the same chromosome D. the bacterial equivalent of eukaryotic chromosomes F. composed of RNA

C

Cytokinesis refers to __________. A. division of the entire cell B. division of the nucleus C. division of the cytoplasm D. reduction in the number of chromosomes E. movement of a cell from one place to another

C

The function of the mitotic cell cycle is to produce daughter cells that __________. A. have the same number of chromatids as the parent cell had chromosomes B. have the same number of chromosomes as the parent cell but not the same genetic content C. have a random assortment of maternal and paternal chromosomes D. are genetically identical to the parent cell (assuming no mutation has occurred) E. None of the listed responses is correct.

D

The region of a chromosome holding the two double strands of replicated DNA together is called __________. A. a chromatid B. chromatin C. a centriole D. a centromere E. an aster

D

What is the difference between a benign tumor and a malignant tumor? A. Benign tumors will not kill you; malignant tumors will. B. Benign tumors arise by transformation; malignant tumors do not. C. Cells of benign tumors metastasize; those of malignant tumors do not. D. Cells of benign tumors do not metastasize; those of malignant tumors do. E. Benign tumors do not arise by transformation; malignant tumors do.

D

Which event or events occur during anaphase? A. A spindle made of microtubules is present B. The centromeres divide C. The centrioles are at opposite poles D. All of the listed responses are correct. E. Identical chromatids move to opposite poles

D

Which of the following events occurs during metaphase of mitosis? A. The sister chromatids are pulled apart toward opposite sides of the cell. B. The nuclear envelope disappears. C. The chromosomes condense. D. The chromosomes align along the metaphase plate of the cell. E. The nuclear envelope forms again. F. The mitotic spindle forms.

D

Which of the following structures is/are part of the mitotic spindle? A. The aster B. Kinetochore microtubules C. Nonkinetochore microtubules D. All of the listed responses are part of the mitotic spindle. E. Centrosome

D

DNA replication occurs in __________. A. the cytokinesis portion of the cell's life cycle B. the G1 phase of interphase in reproductive cells only C. metaphase of meiosis only D. prophase of both mitosis and meiosis E. the S phase of interphase in both somatic and reproductive cells

E

During binary fission in a bacterium __________. A. the two DNA molecules float free in the cell and are guided to daughter cells by a spindle-like apparatus B. the two DNA molecules divide in half, forming four DNA fragments C. the two DNA molecules attach to the centrioles D. the two DNA molecules break up into plasmids E. the origins of replication move apart

E

In animal cell mitosis, the cleavage furrow forms during which stage of the cell cycle? A. Anaphase B. The G1 phase C. Metaphase D. Prophase E. Cytokinesis

E

The complex of DNA and protein that makes up a eukaryotic chromosome is properly called __________. A. a chromatid B. a centromere C. a chromoplast D. a centrosome E. chromatin

E

Which of the following events occurs during anaphase of mitosis? A. The nuclear envelope forms again. B. The chromosomes align along the metaphase plate of the cell. C. The nuclear envelope fragments. D. Spindle fibers attach to the centromeres of the chromosomes. E. The sister chromatids are pulled apart toward opposite sides of the cell. F. The mitotic spindle forms.

E

Which of the following phases of mitosis is essentially the opposite of prometaphase in terms of the nuclear envelope? A. Anaphase B. Metaphase C. S phase D. Interphase E. Telophase

E

How many chromatids does a human somatic cell contain after interphase and just prior to mitosis? A. 46 B. 23 C. 184 D. 22 E. 69 F. 92

F

The spread of cancer cells to other locations in the body is known as __________. A. None of the listed responses is correct. B. chemotherapy C. density-dependent inhibition D. transformation E. a benign tumor F. metastasis

F

Which of the following events occurs during prometaphase of mitosis? A. The nuclear envelope fragments. B. The centrosomes move away from each other. C. The chromosomes align along the metaphase plate of the cell. D. The mitotic spindle forms. E. The nuclear envelope forms again. F. The sister chromatids are pulled toward opposite sides of the cell.

A

Which of the following statements correctly describes the difference(s) between mitosis and binary fission? A. Binary fission involves the replication and division of a single chromosome, whereas mitosis involves the division of multiple, replicated chromosomes. B. There are no differences between binary fission and mitosis. C. Binary fission involves the replication and division of multiple chromosomes, whereas mitosis involves the replication and division of a single chromosome. D. A cell plate forms across the middle of two cells dividing by binary fission, but this does not occur in mitosis. E. Binary fission in bacteria is completed by microtubules, but mitosis does not involve these structures.

A

Observations of cancer cells in culture support the hypothesis that cancer cells __________. A. produce molecules that inhibit the growth factors required for cell division B. do not exhibit density-dependent inhibition C. exhibit anchorage dependence D. spend the majority of their time in the G0 phase E. all of the listed responses are correct

B

Which of the following events does not occur during prophase of mitosis? A. Each duplicated chromosome appears as two identical sister chromatids. B. The centrosomes move away from each other. C. The mitotic spindle breaks down. D. Nucleoli disappear. E. The chromosomes condense F. The mitotic spindle forms.

C

Which of the following events occurs during telophase of mitosis? A. The chromosomes align on the metaphase plate. B. The nuclear envelope fragments. C. Two distinct daughter nuclei form in the cell. D. The sister chromatids separate. E. The chromosomes condense. F. DNA replicates.

C

You would know a dividing cell was a plant cell rather than an animal cell if you saw that __________. A. it had microtubules B. it had two pairs of centrioles during prophase C. it had formed a cell plate D. the nucleolus was visible during metaphase E. it had formed a cleavage furrow

C