Quiz: Cell Cycle and Mitosis Mastery — 10 questions

1. What is DNA in the context of genetic information?

A. A type of carbohydrate used for energy storage

B. A molecule that carries genetic information in living organisms

C. A lipid that makes up the cell membrane

D. A protein that forms the structural components of cells

Answer: (B)

Explanation

DNA is the molecule that carries genetic information in all living organisms, encoding the hereditary instructions necessary for growth, development, and functioning.

2. What is the primary function of DNA in living organisms?

A. To store and transmit genetic information

B. To produce energy for cellular activities

C. To serve as a structural component of the cell membrane

D. To facilitate protein synthesis directly in the cytoplasm

Answer: (A)

Explanation

DNA's main role is to store and transmit genetic information vital for an organism's development, functioning, and reproduction. It does not produce energy (that's ATP), serve as a membrane component, or directly synthesize proteins.

3. What is the primary role of the different phases of the cell cycle?

A. To facilitate growth, repair, and reproduction by ensuring proper DNA duplication and segregation

B. To regulate cell death and apoptosis

C. To generate genetic diversity among daughter cells

D. To produce energy for cellular activities

Answer: (A)

Explanation

The main purpose of the cell cycle phases, including interphase and mitosis, is to prepare the cell for division, ensure accurate DNA replication, and segregate genetic material properly, thereby facilitating growth, tissue repair, and asexual reproduction.

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

A. G1 phase

B. S phase

C. G2 phase

D. Mitosis

Answer: (B)

Explanation

DNA replication occurs during the S (synthesis) phase of interphase, ensuring each new cell inherits a complete set of genetic material. G1 and G2 are preparatory phases, and mitosis is the phase where cell division occurs.

5. How does mitosis differ from the general process of cell division?

A. Mitosis occurs only in reproductive cells, whereas cell division occurs only in somatic cells.

B. Mitosis results in genetically identical daughter cells, while cell division can include processes that produce genetically diverse cells.

C. Mitosis is a process that occurs only in unicellular organisms, whereas cell division occurs in multicellular organisms.

D. Mitosis involves the division of the cytoplasm, while cell division refers only to the division of the nucleus.

Answer: (B)

Explanation

Mitosis is a specific type of cell division that results in two genetically identical daughter cells, which distinguishes it from the broader process of cell division that can include meiosis and other mechanisms. The other options are incorrect because mitosis occurs in somatic cells (not only reproductive cells), involves both nuclear and cytoplasmic division, and occurs in both unicellular and multicellular organisms.

6. What structural change occurs to chromatin during cell division?

A. It condenses to form visible chromosomes

B. It degrades into simpler molecules

C. It transforms into RNA

D. It loses its protein components

Answer: (A)

Explanation

Chromatin condenses into tightly coiled chromosomes during cell division, making the genetic material visible under a microscope. This condensation is essential for accurate segregation of chromosomes.

7. Which of the following best describes a chromosome during cell division?

A. A highly condensed DNA-protein structure that carries genetic information

B. A loosely coiled DNA molecule in the nucleus

C. The cell's organelle responsible for energy production

D. A cell structure involved in protein synthesis

Answer: (A)

Explanation

A chromosome is a highly condensed and organized structure of DNA and proteins that ensures genetic material is accurately transmitted during cell division.

8. What is the key difference between chromatids and chromosomes?

A. Chromatids are identical copies of a chromosome connected at the centromere; chromosomes can be single or double-stranded

B. Chromatids are found only during meiosis while chromosomes are only during mitosis

C. Chromatids are RNA molecules, whereas chromosomes are DNA molecules

D. Chromatids are segments of DNA that do not contain genes

Answer: (A)

Explanation

Chromatids are identical copies of a chromosome created during DNA replication and connected at the centromere; they become chromosomes once separated during cell division.

9. Which author is known for the discovery of the DNA double helix structure along with Watson and Crick in 1953?

A. Rosalind Franklin

B. James Watson and Francis Crick

C. Maurice Wilkins

D. Gregor Mendel

Answer: (B)

Explanation

James Watson and Francis Crick are credited with proposing the correct double helix structure of DNA in 1953, largely based on Rosalind Franklin's X-ray diffraction images.

10. What is the primary purpose of mitosis in multicellular organisms?

A. To produce genetically identical daughter cells for growth, repair, and asexual reproduction

B. To increase genetic diversity within a population

C. To generate gametes for sexual reproduction

D. To convert DNA into RNA molecules for protein synthesis

Answer: (A)

Explanation

Mitosis ensures that each daughter cell receives an identical set of genetic information, supporting growth, tissue repair, and asexual reproduction in multicellular organisms.