Key Area 1.1: Essay Questions

Question 1

Give an account of stem cells under the following headings:

a) embryonic and adult stem cells
b) stem cell research and the therapeutic use of stem cells

Answer 1

a) -stem cells can continue to divide
- can differentiate into any type of cell
- embryonic stem cells are pluripotent
- adult stem cells are multipotent
- adult stem cells in bone marrow give rise to various types of blood cell
b) - stem cells can be used as model cells to study how diseases develop
- stem cells can be used for drug testing
- stem cells can be used in the repair of damaged tissues
- stem cells can be used in the repair of diseases tissues

Question 2

Compare the process of mitosis and meiosis

Answer 2

• mitosis can give rise to somatic cells and germline cells
• mitosis maintains chromosome number in the daughter cells
• mitosis produces two daughter cells
• mitosis produces genetically identical cells
• mitosis produces diploid daughter cells

Question 3

Give an account of cells under the following headings:

a) Somatic cells
b) Germline cells

Answer 3

a) - somatic cells form different types of body tissue (epithelial, muscle, connective, nervous)
- body organs are formed from a variety of these tissues
- somatic cells divide by mitosis
b) - germline cell can divide by mitosis to produce more germline cells
- germline cell can divide by meiosis to price haploid cells
- mutations in germline cells can be passed on to offspring