Question 1: Define what stem cells are and explain one key property that distinguishes them from other cell types.

Answer: Stem cells are undifferentiated cells that can divide to produce specialised cells. One key property is their ability to differentiate into different cell types.

Question 2: Describe the process by which stem cells differentiate into specialised cells.

Answer: Stem cells undergo a process called differentiation, where they activate specific genes that lead to the development of a particular cell type with specialised functions.

Question 1: Explain the role of gene activation in stem cell differentiation.

Answer: Gene activation involves turning on specific genes that code for proteins necessary for a cell’s specialised function, guiding the stem cell to develop into a particular cell type.

Question 2: Identify two factors that can influence stem cell differentiation in the body.

Answer: Signalling molecules (such as growth factors) and the cellular environment influence stem cell differentiation.

Question 1: Describe a typical experiment to investigate the ability of stem cells to differentiate into different cell types.

Answer: An experiment could involve isolating stem cells from a tissue, providing specific growth factors, and observing their differentiation over time into cell types like nerve cells or muscle cells, while controlling variables such as temperature and nutrient supply.

Question 2: List one ethical issue related to the use of embryonic stem cells.

Answer: The destruction of human embryos raises ethical concerns about the moral status of embryos.

Question 1: A study shows that stem cells derived from bone marrow can differentiate into blood cells but not into nerve cells. What does this indicate about the potency of these stem cells?

Answer: It indicates that these stem cells are multipotent, capable of developing into specific cell types within a certain tissue or system, but not into all cell types.

Question 2: A new technology has enabled scientists to reprogram adult skin cells into pluripotent stem cells. How could this impact medical treatments?

Answer: This technology could reduce ethical issues associated with embryonic stem cells, allow for patient-specific treatments, and enable the regeneration of damaged tissues or organs, improving outcomes for conditions like Parkinson’s disease or heart failure.

Question 1: A population of stem cells doubles every 24 hours. If you start with 100 stem cells, how many will there be after 3 days?

Answer: Final population = Initial population × 2^number of days = 100 × 2^3 = 100 × 8 = 800 stem cells