BIO181 Week 09 The Cell Cycle

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

chromatin

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

20

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

92

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

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

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

Cytokinesis

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

Separation of the sister chromatids

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

Telophase

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

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

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

The cell contains more than one nucleus.

Which of the following events occurs during metaphase of mitosis? The mitotic spindle forms. The nuclear envelope forms again. The nuclear envelope disappears. 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 chromosomes align along the metaphase plate of the cell.

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

The nuclear envelope fragments.

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

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

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

Two distinct daughter nuclei form in the cell.

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

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

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

dispersed in the nucleus as long strands of chromatin

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

division of the cytoplasm

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

do not exhibit density-dependent inhibition

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

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

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 the nucleolus was visible during metaphase it had formed a cleavage furrow it had microtubules it had formed a cell plate

it had formed a cell plate

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

metastasis

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

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

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

the S phase of interphase in both somatic and reproductive cells

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

the beginning of the formation of a spindle apparatus

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

All of the listed responses are correct.

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

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

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 do not arise by transformation; malignant tumors do. Cells of benign tumors do not metastasize; those of malignant tumors do. Benign tumors arise by transformation; malignant tumors do not. Benign tumors will not kill you; malignant tumors will.

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

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

The mitotic spindle breaks down.

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

a centromere