Biology Chapter 12 Mastering

The light micrograph shows dividing cells near the tip of an onion root. Identify a cell in each of the following stages: Prophase, Prometaphase, Metaphase, Anaphase, Telophase

A. Anaphase B. Prophase C. Prometaphase D. Metaphase E. Telophase

Eukaryotic chromatin is composed of which of the following macromolecules?

DNA and proteins

Amount of DNA per nucleus over the cell division cycle.G1 is represented by which numbered part(s) of the cell division cycle in the accompanying figure?

I and V

Amount of DNA per nucleus over the cell division cycle. Which region of the accompanying figure represents S phase?

II

Which of the following statements describing kinetochores is correct?

They are sites at which microtubules attach to chromosomes. explanation: As the spindle depolymerizes, the kinetochores appear to move along the spindle fiber, dragging the attached chromosomes with them.

Which of the following statements describes a characteristic feature of metaphase?

alignment of chromosomes on the equator of the cell

Centromeres divide and sister chromatids become full-fledged chromosomes during _____.

anaphase

What is the name of the microtubule-organizing center found in animal cells as an identifiable structure present during all phases of the cell cycle?

centrosome

Cytochalasin B is a chemical that disrupts microfilament formation. With which aspect of cell division would cytochalasin B interfere?

cleavage; the cleavage furrow forms when a ring of microfilaments contracts

One difference between cancer cells and normal cells is that cancer cells

continue to divide even when they are tightly packed together.

Which of the following molecules is synthesized at specific times during the cell cycle and forms an active complex with a kinase?

cyclin

Spindle fibers attach to kinetochores during _____.

prometaphase

Chromosomes become visible during _____.

prophase

Which of the following occurs during SS phase?

replication of the DNA

The mitotic spindle plays a critical role in which of the following processes?

separation of sister chromatids

Cytokinesis often, but not always, accompanies _____.

telophase

What is the name of the region on duplicated chromosomes where the sister chromatids are most closely attached to each other?

the centromere

During _____ both the contents of the nucleus and the cytoplasm are divided.

the mitotic phase (encompasses both mitosis and cytokinesis)

Which of the following molecules is maintained at a relatively constant level throughout the cell cycle but requires a cyclin to become catalytically active?

Cdk

Which statement provides the best description of the interphase portion of the cell cycle?

During interphase, a cell is metabolically active. explanation: Interphase accounts for about 90% of the cell cycle and includes many key events critical to the cell cycle. It is not a resting stage; the cell is metabolically active during this phase.

Which of these phases encompasses all of the stages of mitosis but no other events?

E

If a eukaryotic cell is in the G1 phase of the cell cycle, which statement about the cell's chromosomes must be correct?

Each chromosome is made of a complex of DNA and associated proteins.

Which of the following statements best describes how cytokinesis differs between plant and animal cells?

Plant cells deposit vesicles containing cell wall building blocks on the metaphase plate; animal cells form a cleavage furrow.

Which of the following statements best describes cells in culture that do not exhibit either density-dependent inhibition or anchorage dependence?

The cells show characteristics of tumors.

Which of the following cellular events occur in the G1 phase of the cell division cycle?

normal growth and cell function

After DNA replication, each duplicated chromosome consists of two of which of the following structures?

sister chromatids

Which of the following statements best describes a cleavage furrow?

a groove in the plasma membrane between daughter nuclei

Which of the following correctly matches a phase of the cell cycle with its description? A. G2, cell division B. S, immediately precedes cell division C. G1, follows cell division D. M, duplication of DNA E. All of the listed choices are correctly matched.

C. G1, follows cell division

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

interphase

Nucleoli are present during _____.

interphase

The mitotic spindle consists of two types of microtubules: kinetochore microtubules and nonkinetochore microtubules. In animal cells, these two types of microtubules function differently in the stages of mitosis.

1. Lengthen 2. Lengthen 3. Shorten 4. Disassemble

As the chromosomes of a parent cell are duplicated and distributed to the two daughter cells during cell division, the structure of the chromosomes changes. fill in the blanks with yes or no

1. No, yes, yes ,yes, no 2. No, No, No, yes, yes 3. No, yes, yes, yes, yes

If there are 24 centromeres in a cell at anaphase of mitosis, how many chromosomes will be found in each daughter cell following cytokinesis?

12

Which of the following properties is associated with a cyclin-dependent kinase (Cdk)?

A Cdk is an enzyme that attaches phosphate groups to other proteins.

The figure shows the eukaryotic chromosome as it would appear during interphase, during each of the stages of mitosis, and during cytokinesis. Label the stages, the nuclear envelope and any microtubules attached to the chromosome(s). Drag the appropriate labels to their respective targets. If two labels can be equally placed in two targets the labels should be placed in alphabetical order from top to bottom.

A. Chromatin B. Interphase C. Prophase D. Prometaphase E. Metaphase F. Anaphase G. Cytokinesis H. Telophase I. Nuclear Envelope J. Microtubules K. Nuclear Envelope

Describe the major events occurring at each stage. Use: Prophase, Prometaphase, Metaphase, Anaphase, Telophase

A. Metaphase B. Prometaphase C. Telophase D. Prophase E. Anaphase

The cell cycle represents the coordinated sequence of events in the life of a cell from its formation to its division into two daughter cells. Most of the key events of the cell cycle are restricted to a specific time within the cycle. In this exercise, you will identify when various events occur during the cell cycle. Recall that interphase consists of the G1, S, and G2 subphases, and that the M phase consists of mitosis and cytokinesis. Terms: At this point cell commits to go through cycle, DNA replicates, Mitotic spindle begins to form, Cell divides forming two daughter cells, Non-dividing cells exit the cycle, Two centrosomes have formed,

A. Non-dividing cells exit the cycle B. At this point cell commits to go through cycle C. DNA replicates D. Two centrosomes have formed E. Mitotic spindle begins to form F. Cell divides forming two daughter cells

As in most areas of biology, the study of mitosis and the cell cycle involves a lot of new terminology. Knowing what the different terms mean is essential to understanding and describing the processes occurring in the cell. Terms: centromere(s), sister chromatid(s), interphase, kinetochore(s), mitotic spindle(s), chromatin, centrosome(s), cytokinesis

A. Sister chromatids B. Centromeres C. Kinetochores D. Interphase E. Mitotic spindles F. Chromatin G. Cytokinesis H. Centrosomes

Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in

G1

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

G1 (this checkpoint can also be called the restriction point)

Amount of DNA per nucleus over the cell division cycle. Which numbered regions of the accompanying figure represent the DNA content associated with cells at metaphase?

III only

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 plant cell in the process of cytokinesis.

Which of the following events characterizes the beginning of anaphase?

enzymatic cleavage of cohesion

Students in a biology lab isolated cells in various phases of the cell cycle. A population of cells that have 1 1/2 times the DNA of G1 phase cells was most likely isolated from which of the following parts of the cell cycle?

in the S phase

Why is it difficult to observe individual chromosomes with a light microscope during interphase?

interphase chromosomes are long, thin strands unlike the condensed chromosomes visible in mitosis explanation: Except during the M phase, the DNA is extended, allowing its genes to be transcribed for protein synthesis.

Movement of the chromosomes during anaphase would be most directly affected by a drug that prevents which of the following events?

shortening of microtubules Submit