1. A somatic cell divides to form two genetically identical daughter cells durin

ID: 63462 • Letter: 1

Question

1. A somatic cell divides to form two genetically identical daughter cells during mitosis. Prior to mitosis occurring, which of the following must occur?

a. The cell must replicate its DNA.

b. The cell must first be fertilized.

c. The nucleus must divide.

d. Chromatids must be separated.

e. The nuclear envelope must disintegrate.

2. A diploid cell with 40 chromosomes will have ____ chromosomes and _____ chromatids after S phase.

a. 20, 40

b. 20, 20

c. 40, 40

d. 40, 80

e. 80, 80

3. Chromatin condenses into chromosomes and the mitotic spindle begins to form during

a. interphase.

b. prophase.

c. metaphase.

d. anaphase.

e. telophase.

4. Chromosomes decondense into chromatin at which point in the cell cycle?

a. at the beginning of interphase

b. at the end of interphase

c. at the beginning of prophase

d. at the beginning of metaphase

e. at the end of telophase

5. Comparison of mitosis and cytokinesis in animal versus plant cells reveals ____.

a. sister chromatids are identical in animal cells, but they differ from one another in plants

b. a cleavage furrow is initiated in an animal cell, while a cell plate begins to form in plant cells during telophase

c. in animal cells, chromosomes do not become attached to the spindle until anaphase, whereas chromosomes become attached to the spindle at prophase in plant cells

d. the nuclear envelope disintegrates in prophase in animal cells, but remains intact in plant cells

e. There are no differences between animal and plant cells.

6. Certain cell types in humans, such as skeletal muscle cells, have several nuclei per cell. Based on your understanding of mitosis, how could this happen?

a. The cell undergoes repeated cytokinesis but not mitosis.

b. The cell undergoes repeated mitosis with concomitant cytokinesis.

c. The cell undergoes repeated mitosis but not cytokinesis.

d. The cell undergoes anaphase twice before entering telophase.

e. The cell goes through multiple S phases before entering mitosis.

7. Organisms that reproduce asexually usually do so through the process of ____.

a. mitosis

b. meiosis

c. gametogenesis

d. spore formation

e. fertilization

8. The microtubule organizing center (MTOC) of an animal cell is an identifiable structure known as the ____.

a. cell plate

b. centrosome

c. kinetochore

d. centromere

e. chromosome

9. CDKs are protein kinases. They function to ____.

a. add phosphate groups to target proteins

b. check for the attachment of spindle fibers to chromosomes

c. remove phosphate groups from cyclins

d. arrest the cell cycle

e. allow the cell cycle to work forward or backward

10. If a cell's DNA becomes damaged by radiation or chemicals, it is unlikely to ____.

a. pass the G2 checkpoint

b. synthesize cyclin-dependent kinases

c. enter G1 from mitosis

d. become arrested in G1

e. activate DNA repair mechanisms

11. Progression through the phases of the cell cycle is regulated by fluctuating concentrations of ____.

a. microtubules

b. actin

c. cyclins

d. cyclin-dependent kinases

e. histones

12. Contact inhibition is best explained by which of the following statements?

a. Contact between neighboring cells triggers reactions leading to inhibition of mitosis.

b. As neighboring cells become more tightly packed together, their size is restricted and cytokinesis can no longer occur.

c. As cell number increases, the protein kinases they produce compete with neighboring cells, inhibiting mitosis.

d. As cell number increases, the level of waste products increase, consequently slowing metabolism leading to mitosis.

e. As cell number increases, size restrictions inhibit protein synthesis.

13. Vinblastine, a chemotherapeutic drug used to treat breast and testicular cancers, interferes with the assembly of microtubules. Speculate how this drug works to inhibit cancer cell growth.

a. Vinblastine inhibits transition from G1 to S.

b. Vinblastine inhibits transition from S to mitosis.

c. Vinblastine inhibits cytokinesis.

d. Vinblastine disrupts mitotic spindle formation and consequently mitosis.

e. Vinblastine inhibits cyclin production.

14. Herpesvirus 8 encodes a protein that acts as a(n) ____.

a. tumor suppressor

b. transcription factor

c. cyclin

d. polymerase

e. enzyme

15. Which of the following is true about binary fission?

a. It is thought to have evolved from mitosis.

b. It is used in gamete formation.

c. It results in the production of two identical daughter cells.

d. It requires spindle formation.

e. It is used during eukaryotic cell growth.

Explanation / Answer