Question 1: Define mitosis and briefly describe its main purpose in multicellular organisms.

Answer: Mitosis is a type of cell division where a single parent cell divides to produce two genetically identical daughter cells. Its main purpose is growth, repair, and asexual reproduction in multicellular organisms.

Question 2: List the stages of mitosis in the correct order.

Answer: Prophase, Metaphase, Anaphase, Telophase.

Question 3: During mitosis, when chromosomes are aligned at the cell's equator, which stage is occurring?

Answer: Metaphase

Question 4: Calculate the duration of mitosis if a cell takes 24 minutes to complete the process, and interphase accounts for 75% of the cell cycle.

Answer: Interphase duration = 0.75 × 24 minutes = 18 minutes; Mitosis duration = 24 - 18 = 6 minutes.

Question 5: If a population of cells has 16 cells in metaphase, and the total number of cells in mitosis is 80, what is the mitotic index? Show your calculation.

Answer: Mitotic index = (Number of cells in mitosis / Total number of cells) × 100 = (80 / total cells) × 100. But since only 16 are in metaphase, and total in mitosis is 80, we need total cells. Assuming total cells are 400, mitotic index = (80 / 400) × 100 = 20%.

Question 6: Describe one safety precaution you should take when observing mitosis using a microscope.

Answer: Always handle glass slides carefully to avoid cuts, and use a microscope with proper eye protection if necessary.

Question 7: Explain how the spindle fibres facilitate chromosome separation during mitosis.

Answer: Spindle fibres, which are microtubules, attach to the centromeres of chromosomes during metaphase. They then shorten during anaphase, pulling sister chromatids apart to opposite poles of the cell, ensuring each daughter cell receives an identical set of chromosomes.

Question 8: A scientist observes that a cell has 92 chromosomes during metaphase. How many chromosomes will each daughter cell have after mitosis?

Answer: Each daughter cell will have 92 chromosomes, as mitosis produces genetically identical cells.

Question 9: Identify two factors that can influence the rate of mitosis in tissues.

Answer: Availability of nutrients and the presence of growth factors or hormones.

Question 10: Describe a real-world application of understanding mitosis in medical science or industry.

Answer: Understanding mitosis is essential in cancer treatment, where uncontrolled cell division occurs. Targeted therapies aim to inhibit specific stages of mitosis to prevent tumour growth. Additionally, in tissue engineering, controlling mitosis helps in regenerating damaged tissues.