Mastering Biology Chapter 9

Which of these phases encompasses all of the stages of mitosis but no other events? The figure shows the pie chart of the cell cycle, which consists of two parts. The bigger part of this pie chart, labeled C, divides into three sectors. The second sector is labeled D. The smaller part of the pie chart divides into two sectors. The first is marked A, the second - B. A D C E B

E

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? M G0 S G1 G2

G1

cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle? Hints M G1 cytokinesis S G2

G1

The ________ is a cell structure consisting of microtubules, which forms during early mitosis and plays a role in cell division.

mitotic spindle(s)

What is produced if a cell completes mitosis but does not undergo cytokinesis? two cells, one cell containing two nuclei and a second cell without a nucleus one cell with two nuclei, each identical to the nucleus of the parent cell two cells, each cell with half of the genetic material of the parent cell one cell with one nucleus containing half of the genetic material of the parent cell two cells, each cell with an identical nucleus containing the genetic material of the parent cell

one cell with two nuclei, each identical to the nucleus of the parent cell

If there are 20 centromeres in a cell at anaphase of mitosis, how many chromosomes are there in each daughter cell following cytokinesis? 5 10 20 40

10

Beginning with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? 4 8 16 32 64

32

A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain? Hints 46 or 92, depending on the portion of prophase examined 23 or 46, depending on the portion of prophase examined 23 92 46

92

How do cancer cells differ from normal cells? Cancer cells trigger chromosomal changes in surrounding cells. Cultured cancer cells exhibit anchorage dependence. Cancer cells may be immortal.

Cancer cells may be immortal.

Which statement provides the best description of the interphase portion of the cell cycle? During interphase, a cell is metabolically active. Interphase is a resting stage prior to cell division. Interphase is a brief period between mitosis and chromosome duplication.

During interphase, a cell is metabolically active

Which of the following is found in binary fission but not in mitosis? Hints Replication of DNA begins at an origin. Following the process, a membrane separates the 2 copies. The result produces 2 nuclei. Duplicated chromosomes attach to the plasma membrane. Replicated strands of DNA separate.

Duplicated chromosomes attach to the plasma membrane.

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 __________. G2 metaphase G1 prophase

G1

Which of the following correctly matches a phase of the cell cycle with its description? Hints G2: cell division G1: follows cell division M: duplication of DNA S: immediately precedes cell division All of the listed responses are correctly matched.

G1: follows cell division

Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? Golgi-derived vesicles tubulin and dynein centrioles and centromeres actin and myosin spot desmosomes

Golgi-derived vesicles

What is true of all cancers? They are caused by chemical carcinogens. They are inherited. They have escaped normal cell cycle controls.

They have escaped normal cell cycle controls.

Which of the following is true of benign tumors but not malignant tumors? Hints They remain confined to their original site. They migrate from the initial site of transformation to other organs or tissues. They can divide indefinitely if an adequate supply of nutrients is available. They have an unusual number of chromosomes. They are the result of the transformation of normal cells.

They remain confined to their original site.

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely __________. a bacterial cell dividing a plant cell in the process of cytokinesis an animal cell in the process of cytokinesis a plant cell in metaphase

a plant cell in the process of cytokinesis

Which of these is NOT a carcinogen? UV light fat testosterone cigarette smoke all of the above are carcinogens

all of the above are carcinogens

After chromosomes condense, the ______ is the region where the identical DNA molecules are most tightly attached to each other.

centromere(s)

The ____________ are the organizing centers for microtubules involved in separating chromosomes during mitosis.

centrosome(s)

During interphase, most of the nucleus is filled with a complex of DNA and protein in a dispersed form called

chromatin.

Cytochalasin B is a chemical that disrupts microfilament formation. How would this interfere with cell division? Hints formation of the mitotic spindle cleavage binary fission formation of the cell plate DNA replication

cleavage

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? spindle attachment to kinetochores cell elongation during anaphase cleavage furrow formation and cytokinesis spindle formation

cleavage furrow formation and cytokinesis

In most eukaryotes, division of the nucleus is followed by _________ when the rest of the cell divides.

cytokinesis,

During telophase, the nonkinetochore microtubules __________ .

disassemble

_____ is a carcinogen that promotes colon cancer. fat UV light estrogen a virus testosterone

fat

During _____ the cell grows and replicates both its organelles and its chromosomes. interphase G1 mitosis cytokinesis S

interphase

In dividing cells, most of the cell's growth occurs during _________

interphase.

During mitosis, microtubules attach to chromosomes at the _________

kinetochore(s).

During prophase, the microtubules of the mitotic spindle _______ .

lengthen

During anaphase, the nonkinetochore microtubules _______ and move past each other, and the kinetochore microtubules_______ .

lengthen shorten

During mitosis in animal cells, at which phase do centrioles begin to move apart? prometaphase prophase metaphase anaphase telophase

prophase

Which of the following does NOT occur during mitosis? replication of the DNA condensation of the chromosomes spindle formation separation of sister chromatids

replication of DNA

. DNA replication produces two identical DNA molecules, called ______ which separate during mitosis.

sister chromatid(s),

During _____ both the contents of the nucleus and the cytoplasm are divided. S mitosis G1 the mitotic phase G2

the mitotic phase

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

twice as much DNA as the nuclei of gametes produced by meiosis.