Question 1: Define stem cells and explain their unique ability to differentiate.

Answer: Stem cells are undifferentiated cells that can develop into different cell types and have the ability to divide and renew themselves.

Question 2: Name two sources of adult stem cells in the human body.

Answer: Bone marrow and blood.

Question 1: If a single stem cell divides every 24 hours, how many stem cells will be present after 5 days? (Assuming no cell death and continuous division). Use the formula: N = N0 * 2^n, where N0 is initial cells, n is number of divisions.

Answer: 512

Question 2: Calculate the total number of new cells produced after 3 divisions starting from 1 stem cell. Use the formula: Total new cells = N - 1, where N is the total number of cells after divisions.

Answer: 7

Question 1: Describe a basic experimental setup to test the ability of stem cells to differentiate into nerve cells in a laboratory setting.

Answer: An experiment could involve culturing stem cells in a specialized growth medium containing nerve growth factors and observing morphological changes over time to confirm differentiation into nerve cells.

Question 2: Identify two safety precautions that must be taken when working with stem cells in a laboratory.

Answer: Using sterile techniques to prevent contamination and wearing protective equipment like gloves and lab coats.

Question 1: A study reports that 10 million stem cells are injected into a damaged tissue, and after one week, the cell count increases by 150%. How many stem cells are present after one week?

Answer: 25 million

Question 2: If the rate of stem cell differentiation into specialized cells in a tissue is 5% per day, how many cells differentiate after 7 days from an initial population of 1,000 stem cells?

Answer: 350

Question 1: Explain the potential benefits and ethical considerations of using stem cells in regenerative medicine. (6 marks)

Answer: Stem cells have the potential to regenerate damaged tissues and treat diseases, offering hope for conditions like spinal cord injuries and heart disease. However, ethical issues arise regarding the source of stem cells, particularly embryonic stem cells, and concerns about consent, cloning, and potential misuse. Responsible research and regulation are essential to balance scientific advancement with ethical standards.

Question 1: Describe how stem cell therapy is used in treating leukemia.

Answer: Stem cell therapy involves transplanting healthy blood-forming stem cells from a donor into a patient to replace diseased or damaged bone marrow, helping to restore normal blood production.

Question 2: Identify two industries that utilize stem cell research and technologies.

Answer: Medical research and pharmaceutical industries.