MPF_{activity} = Cyclin \times Cdk

Question 1

Which of the following best describes the difference between mitosis and meiosis in terms of genetic outcomes?

Accepted Answer

Mitosis produces genetically identical daughter cells, while meiosis produces genetically different daughter cells with half the hereditary material.

Question 2

During which phase of the cell cycle does DNA replication occur?

Accepted Answer

S phase

Question 3

What is the primary function of the spindle apparatus during mitosis?

Accepted Answer

To move and separate replicated chromosomes

Question 4

Which structure is responsible for attaching microtubules to chromosomes during prometaphase?

Accepted Answer

Kinetochore

Question 5

A cell is observed to have chromosomes lined up along the metaphase plate. Which phase of mitosis is this cell in?

Accepted Answer

Metaphase

Question 6

What is the role of the p53 protein at the G1 checkpoint?

Accepted Answer

It activates proteins that pause the cell cycle or initiates apoptosis if DNA is damaged.

Question 7

Which of the following equations best represents the relationship between cyclin concentration and MPF activity?

Accepted Answer

MPF_{activity} = Cyclin 	imes Cdk

Question 8

During cytokinesis in plant cells, what structure forms to separate the two daughter cells?

Accepted Answer

Cell plate

Question 9

Which checkpoint ensures that all kinetochores are attached to the spindle apparatus before sister chromatids split?

Accepted Answer

M-phase checkpoint (between metaphase and anaphase)

Question 10

A mutation causes the Rb protein to be unable to bind E2F. What is the likely consequence for the cell?

Accepted Answer

E2F will activate genes for S phase, leading to uncontrolled cell division.

Question 11

Which of the following best describes the process of binary fission in bacteria?

Accepted Answer

Bacterial chromosomes are replicated, filaments pull chromosomes apart, and proteins divide the cytoplasm.

Question 12

Which of the following is a property of malignant tumors?

Accepted Answer

They can spread throughout the body via blood or lymph and initiate secondary tumors.

Question 13

If a cell fails to pass the G2 checkpoint due to incomplete DNA replication, what happens to MPF?

Accepted Answer

MPF remains inactive and the cell does not enter M phase.

Question 14

Which of the following best explains how negative feedback regulates MPF activity?

Accepted Answer

An enzyme complex marks cyclin for destruction, leading to MPF deactivation.

Question 15

A researcher observes that a cell is dividing without the presence of growth factors. Which cellular defect is most likely present?

Accepted Answer

Overproduction of cyclin permanently activates Cdk, bypassing the G1 checkpoint.

Question 16

Which of the following events occurs during anaphase of mitosis?

Accepted Answer

Cohesions holding sister chromatids split and chromatids are pulled toward opposite poles.

Question 17

Which equation best represents the process of phosphorylation by a protein kinase?

Accepted Answer

$$Protein + ATP \rightarrow Protein{-}P + ADP$$

Question 18

Which of the following is NOT a function of the cell cycle checkpoints?

Accepted Answer

Promoting uncontrolled cell division in response to growth factors.

Question 19

A cell is observed to have a ring of actin and myosin filaments contracting inside the cell membrane. What process is occurring?

Accepted Answer

Cytokinesis in animal cells

Question 20

Which of the following statements about the cell cycle is correct?

Accepted Answer

Interphase consists of G1, S, and G2 phases.

The Cell Cycle: Structure, Function, and Regulation

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