Question 1

Which phase of the cell cycle is responsible for the duplication of chromosomes, and what is the correct number of DNA copies present at the end of this phase in a human somatic cell?

Accepted Answer

S phase; two copies of DNA per chromosome

Question 2

During which stage of mitosis do the sister chromatids separate, and what enzyme is responsible for cleaving the cohesins that hold them together?

Accepted Answer

Anaphase; separase

Question 3

A researcher observes a cell with condensed chromosomes, a disassembled nuclear envelope, and spindle microtubules attaching to kinetochores. Which stage of mitosis is this cell most likely in?

Accepted Answer

Prometaphase

Question 4

Which of the following best describes the difference between cytokinesis in animal cells and plant cells?

Accepted Answer

Animal cells form a cleavage furrow, while plant cells form a cell plate.

Question 5

Which checkpoint in the cell cycle is considered the most important for determining whether a cell will proceed to divide, and what happens if the cell does not receive the go-ahead signal at this checkpoint?

Accepted Answer

G$_1$ checkpoint; the cell enters G$_0$ phase

Question 6

Which molecular complex triggers a cell’s passage past the G$_2$ checkpoint into M phase, and what are its components?

Accepted Answer

MPF; cyclin and cyclin-dependent kinase (Cdk)

Question 7

A scientist is culturing fibroblast cells and notices that they stop dividing when crowded, but resume division when some cells are removed. Which phenomenon is being observed?

Accepted Answer

Density-dependent inhibition

Question 8

Which of the following statements about cancer cells is TRUE?

Accepted Answer

Cancer cells can divide indefinitely due to transformation.

Question 9

In binary fission, which is the correct sequence of events for bacterial cell division?

Accepted Answer

Chromosome replicates, daughter chromosomes move apart, plasma membrane pinches inward, cell divides

Question 10

A cell is observed to have two sets of chromosomes. What type of cell is this, and what is the term for its chromosome number?

Accepted Answer

Somatic cell; diploid

Question 11

Which of the following is a function of cell division in multicellular eukaryotes?

Accepted Answer

Embryonic development

Question 12

What is the role of the mitotic spindle during mitosis?

Accepted Answer

It controls chromosome movement during mitosis.

Question 13

Which of the following best explains why most animal cells require attachment to a substratum to divide?

Accepted Answer

To receive anchorage-dependent signals for cell cycle progression

Question 14

A patient is diagnosed with a tumor that invades surrounding tissues and spreads to other parts of the body. What is the correct term for this type of tumor?

Accepted Answer

Malignant tumor

Question 15

If a cell receives a go-ahead signal at the G$_1$ checkpoint, which phases will it complete before dividing?

Accepted Answer

S, G$_2$, and M phases

Question 16

Which of the following is TRUE regarding the genome of prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic genomes consist of chromatin organized into chromosomes.

Question 17

Which regulatory proteins are required for the activation of cyclin-dependent kinases (Cdks) in the cell cycle?

Accepted Answer

Cyclins

Question 18

A cell is exposed to platelet-derived growth factor (PDGF) in culture. What is the expected response of fibroblast cells to PDGF?

Accepted Answer

They begin dividing in response to the growth factor.

Question 19

Which of the following best describes the process by which cancer cells spread to other parts of the body?

Accepted Answer

Metastasis

Question 20

A cell is observed to have a radial array of short microtubules extending from each centrosome. What is this structure called, and what is its function?

Accepted Answer

Aster; helps position the spindle apparatus

The Cell Cycle: Structure, Function, and Regulation

Study Guide - Practice Questions

Study Guide - Flashcards