Chapter 12: The Cell Cycle

Which of the following events does not occur during interphase of the cell cycle? Separation of the sister chromatids Duplication of the chromosomes Production of new mitochondria Production of the endoplasmic reticulum Protein production Growth of the cell

Separation of the sister chromatids

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

it has formed a cell plate

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

- the origins of replication move apart

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

20

How many chromatids does a human somatic cell contain after interphase and just prior to mitosis? 46 184 22 69 92 23

92

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

chromatin

In animal cell mitosis, the cleavage furrow forms during which stage of the cell cycle? The G1 phase Cytokinesis Metaphase Anaphase Prophase

cytokinesis

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

division of the cytoplasm

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

metastasis

Which of the following phases of mitosis is essentially the opposite of prometaphase in terms of the nuclear envelope? Telophase Interphase S phase Metaphase Anaphase

telophase

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

the beginning of the formation of a spindle apparatus

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

two distinct daughter nuclei form in the cell

Which of the following structures is/are part of the mitotic spindle? - All of the listed responses are part of the mitotic spindle. - Nonkinetochore microtubules - Kinetochore microtubules - The aster - Centrosome

- All of the listed responses are part of the mitotic spindle.

Which of the following statements correctly describes the difference(s) between mitosis and binary fission? - Binary fission in bacteria is completed by microtubules, but mitosis does not involve these structures. - There are no differences between binary fission and mitosis. - A cell plate forms across the middle of two cells dividing by binary fission, but this does not occur in mitosis. - Binary fission involves the replication and division of a single chromosome, whereas mitosis involves the division of multiple, replicated chromosomes. - Binary fission involves the replication and division of multiple chromosomes, whereas mitosis involves the replication and division of a single chromosome. - None of the listed responses is correct.

- Binary fission involves the replication and division of a single chromosome, whereas mitosis involves the division of multiple, replicated chromosomes.

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

- Cells of benign tumors do not metastasize; those of malignant tumors do.

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? - The DNA was replicated during the G2 phase of interphase. - The DNA was replicated prior to interphase. - The DNA was replicated after the G2 phase of interphase. - The DNA was replicated during the G1 phase of interphase. - The DNA was replicated during the S phase of interphase, which occurs between the two G phases. - The DNA was not replicated. This was the result of a mutation.

- The DNA was replicated during the S phase of interphase, which occurs between the two G phases.

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

- The chromosomes align along the metaphase plate of the cell.

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

- The nuclear envelope fragments in most eukaryotes but remains intact in diatoms and dinoflagellates.

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

- The nuclear envelope fragments.

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

- The sister chromatids are pulled apart toward opposite sides of the cell.

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

- are genetically identical to the parent cell (assuming no mutation has occurred)

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

- dispersed in the nucleus as long strands of chromatin

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

- do not exhibit density-dependent inhibition

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

- identical copies of each other if they are part of the same chromosome

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

- regulate the cell cycle through a variety of stop and go signals

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

- the S phase of interphase in both somatic and reproductive cells

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

All of the listed responses are correct.

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

The cell contains more than one nucleus.

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

a centromere

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

the mitotic spindle breaks down