Question 1: Define stem cells and explain their primary characteristic that distinguishes them from other cell types.

Answer: Stem cells are undifferentiated cells capable of dividing and renewing themselves, with the potential to develop into specialized cell types.

Question 2: What are the two main types of stem cells based on their potential to differentiate?

Answer: Embryonic stem cells and adult (somatic) stem cells.

Question 1: Describe the process by which a stem cell differentiates into a specific cell type.

Answer: Stem cell differentiation involves the activation of specific genes and signaling pathways that lead to the development of distinct structural and functional features of specialized cells.

Question 2: Explain why stem cells are considered valuable in medical research and therapy.

Answer: Because they can develop into different cell types, they are used for repairing damaged tissues, studying disease processes, and developing regenerative treatments.

Question 1: If a sample contains 1,000 stem cells and each cell divides every 24 hours, how many stem cells will there be after 3 days? (Use the formula: Final cell number = initial number × 2^number of divisions).

Answer: Final cell number = 1000 × 2^3 = 1000 × 8 = 8000

Question 1: List three safety precautions that should be followed during laboratory work involving stem cells.

Answer: Wearing gloves and protective clothing, sterilizing equipment, and proper disposal of biological waste.

Question 2: Identify two ethical concerns associated with the use of embryonic stem cells in research.

Answer: Ethical issues include the destruction of embryos and the moral status of embryos.

Question 1: A research study reports that 85% of adult stem cells successfully differentiate into nerve cells under specific conditions. What does this percentage tell you about the efficiency of this differentiation process?

Answer: It indicates that the process is relatively efficient, with the majority of stem cells successfully becoming nerve cells under those conditions.

Question 1: Describe one way stem cells are used in medical treatments today.

Answer: Stem cells are used in bone marrow transplants to treat certain blood disorders like leukemia.

Question 2: What are some challenges or limitations faced in the use of stem cell therapies?

Answer: Challenges include immune rejection, ethical concerns, limited availability of embryonic stem cells, potential for tumor formation, and technical difficulties in controlling differentiation and integration into tissues.