Question 1

Which of the following best describes the main function of cell division in multicellular organisms?

Accepted Answer

To replace damaged or lost cells, permit growth, and enable development

Question 2

During which phase of the cell cycle does DNA replication occur, and what is the result for each chromosome?

Accepted Answer

S phase; each chromosome consists of two identical sister chromatids

Question 3

A researcher observes a cell with chromosomes aligned at the center of the cell, attached to spindle fibers. Which stage of mitosis is this cell in?

Accepted Answer

Metaphase

Question 4

Which of the following statements about somatic cells and gametes in humans is correct?

Accepted Answer

Somatic cells are diploid with 46 chromosomes, while gametes are haploid with 23 chromosomes

Question 5

What is the role of cyclin-dependent kinases (Cdks) in the cell cycle?

Accepted Answer

They regulate the cell cycle by activating transitions between phases when bound to cyclins

Question 6

A cell is observed to have a fragmented nuclear envelope, spindle fibers attaching to kinetochores, and chromosomes moving. Which mitotic stage is this?

Accepted Answer

Prometaphase

Question 7

Which checkpoint in the cell cycle is primarily responsible for ensuring that DNA is not damaged before replication proceeds?

Accepted Answer

G1 checkpoint

Question 8

A mutation in the gene encoding the enzyme telomerase is most likely to affect which aspect of cell division?

Accepted Answer

The length of telomeres, potentially leading to uncontrolled cell division or cancer

Question 9

Which of the following best explains why cancer cells can form tumors?

Accepted Answer

They do not respond to density-dependent inhibition or anchorage dependence

Question 10

In plant cells, cytokinesis differs from animal cells in that:

Accepted Answer

A cell plate forms from vesicles that fuse at the center of the cell

Question 11

A scientist is studying a cell that has just completed DNA replication but has not yet started mitosis. Which phase is the cell in?

Accepted Answer

G2 phase

Question 12

Which of the following equations correctly represents the change in chromosome number during mitosis in a human somatic cell?

Accepted Answer

$$2n \rightarrow 2n$$

Question 13

Which protein is activated in response to DNA damage at the G1 checkpoint and can induce apoptosis if the damage is irreparable?

Accepted Answer

p53

Question 14

A patient is treated with a chemotherapeutic drug that disrupts microtubule formation. Which stage of mitosis would be most directly affected?

Accepted Answer

Metaphase

Question 15

Which of the following is a correct sequence of events during mitosis?

Accepted Answer

Prophase → Metaphase → Anaphase → Telophase

Question 16

Which of the following best describes the difference between a benign and a malignant tumor?

Accepted Answer

Malignant tumors can metastasize to other parts of the body, while benign tumors remain at the original site

Question 17

Which of the following is a real-world example of asexual reproduction in multicellular organisms?

Accepted Answer

A sea star regenerating a new individual from a fragmented arm

Question 18

Which of the following best explains why most cells in the human body are in the G0 phase?

Accepted Answer

They are in a non-dividing state unless repair or replacement is needed

Question 19

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

Accepted Answer

The chromosome is replicated, and the plasma membrane pinches inward to divide the cell

Question 20

A wound in the skin triggers the release of platelet-derived growth factor (PDGF). What is the most direct effect of PDGF in this scenario?

Accepted Answer

It stimulates fibroblasts to divide and repair the wound

Cell Division and the Cell Cycle: Structure, Function, and Regulation

Guida di studio - Domande di pratica

Study guide - Flashcard