9 The Cell Cycle Flashcards

Question 1

Q

Which of these phases encompasses all of the stages of mitosis?

Question 2

Q

Cell division occurs during this short phase, which generally involves two discrete processes: the contents of the nucleus (mainly the duplicated chromosomes) are evenly distributed to two daughter nuclei, and the cytoplasm divides in two.

Answer

A

Mitotic Phase (M)

Question 3

Q

DNA synthesis (or replication) occurs during this phase. At the beginning of the phase, each chromosome is single. At the end, after DNA replication, each chromosome consists of two sister chromatids.

Answer

A

S Phase ( D )

Question 4

Q

Typically, this phase accounts for 90% of the cell cycle. It is a time of high metabolic activity. The cell grows by producing proteins and organelles, and chromosomes are replicated.

Answer

A

Interphase ( C )

Question 5

Q

This is when division of the nucleus occurs. The chromosomes that have been replicated are distributed to two daughter nuclei.

Answer

A

Mitosis ( E )

Question 6

Q

This third subphase of interphase is a period of metabolic activity and growth. During this phase the cell makes final preparations for division.

Question 7

Q

This is the portion of the cell cycle just after division, but before DNA synthesis. During this time the cell grows by producing proteins and organelles.

Question 8

Q

This is the step in the cell cycle when the cytoplasm divides in two.

Answer

A

Cytokinesis ( B )

Question 9

Q

During _____ the cell grows and replicates both its organelles and its chromosomes.

Answer

A

Interphase

Question 10

Q

Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis?

Answer

A

The chromosomes are “reeled in” by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules.

Question 11

Q

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?

Answer

A

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

Question 12

Q

Which of the following correctly matches a phase of the cell cycle with its description?

G₂: cell division G₁: follows cell division M: duplication of DNA S: immediately precedes cell division All of the above are correctly matched.

Answer

A

G₁: follows cell division

After mitosis and cytokinesis, the newly formed daughter cells enter the G₁ phase.

Question 13

Q

In some organisms, such as certain fungi and algae, cells undergo the cell cycle repeatedly without subsequently undergoing cytokinesis. What would result from this?

Answer

A

large cells containing many nuclei

Question 14

Q

What is a cleavage furrow?

Answer

A

a groove in the plasma membrane between daughter nuclei

Question 15

Q

If the cell whose nuclear material is shown in Figure 12.2 continues toward completion of mitosis, which of the following events would occur next?

Answer

A

formation of telophase nuclei

Question 16

Q

Cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle?

Answer

A

G₁

In mammalian cells, this checkpoint is termed the restriction point.

Question 17

Q

Which of the following is a function of the S phase in the cell cycle?

Answer

A

The synthesis of sister chromatids

Question 18

Q

The copying of chromosomes occurs during which of the following phases of the cell cycle?

Question 19

Q

True or false? The M phase is characterized by the replication and division of a cell’s chromosomes.

Answer

A

False: Cells replicate their chromosomes during the S phase and divide partition their chromosomes during the M phase.

Question 20

Q

The centromere is a region in which

Answer

A

chromatids remain attached to one another until anaphase.

Question 21

Q

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

Answer

A

Sister Chromatids

Question 22

Q

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

Answer

A

Centromere

Question 23

Q

During Mitosis, microtubules attach to chromosomes at the _______.

Answer

A

Kinetochore

Question 24

Q

In dividing cells, most of the cell’s growth occurs during ______.

Answer

A

Interphase

Question 25

Q

The ____________ is a cell structure consising of microtubules, which forms during early mitosis and plays a role in cell division

Answer

A

Mitotic Spindle

Question 26

Q

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

Answer

A

Chromatin

Question 27

Q

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

Answer

A

Cytokinesis

Question 28

Q

The ________ are the organzing centers for mcrotubules involed in seperatng chromasomes during mitosis

Answer

A

Centrosomes

Question 29

Q

A mass of abnormal cells with specific genetic and cellular changes such that the cells are not capable of surviving at a new site and generally remain at the site of the tumor’s origin.

Answer

A

Benign Tumor

Benign tumors can often be surgically removed because their boundaries are well defined, whereas some malignant tumors go on to metastasize.

Question 30

Q

A method of asexual reproduction by “division in half.” In prokaryotes, binary fission does not involve mitosis, but in single-celled eukaryotes that undergo binary fission, mitosis is part of the process.

Answer

A

Binary Fission

Question 31

Q

A cancerous tumor containing cells that have significant genetic and cellular changes and are capable of invading and surviving in new sites. Malignant tumors can impair the functions of one or more organs.

Answer

A

Malignant Tumor

Question 32

Q

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

Answer

A

a plant cell in the process of cytokinesis

Question 33

Q

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in

Answer

A

cells with more than one nucleus.

Question 34

Q

Which of the following does not occur during mitosis?

Answer

A

replication of the DNA

Question 35

Q

Which of the following is true concerning cancer cells?

Answer

A

When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when growing in culture.

Question 36

Q

Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor?

Answer

A

Lack of appropriate cell death

Cancer cells can go on dividing indefinitely in culture if they are given a continual supply of nutrients; in essence, they are “immortal.” Read about HeLa cells

Question 37

Q