(CELL BIO) Cell Division

Question 1

What are chromosomes made of?

Answer 1

DNA molecules combined with proteins. The contain genes which provide the instructions for protein synthesis

Question 2

What is a gene?

Answer 2

A section of DNA which codes for a protein

Question 3

How many chromosomes are found in the nucleus of human body cells?

Answer 3

46 (23 pairs)

Question 4

How many chromosomes are found in the nucleus of gametes?

Answer 4

23

Question 5

What are the three main stages of the cell cycle?

Answer 5

• Replication of DNA and synthesis of the organelles
• Mitosis
• Division of cell

Question 6

Why is mitosis important?

Answer 6

• Produces identical cells which all have the same genetic information
• Produces additional cells for growth and repair

Question 7

What is a stem cell?

Answer 7

Unspecialised cell which is capable of differentiating into other cell types and of self-renewal.

Question 8

What is the function of stem cells in embryos?

Answer 8

Embryonic stem cells can replicate themselves and differentiate into many other types of cells.
They may also be able to treat conditions such as paralysis and diabetes by dividing to replace damaged cells.

Question 9

What are the advantages of cloning plants using meristem stem cells?

Answer 9

• Can prevent rare plants from going extinct
• Can produce a large number of plants with a favourable characteristic
• Can produce identical plants for research

Question 10

What are the issues that are associated with the use of stem cells?

Answer 10

• many embryonic stem cells are sourced from aborted embryos and some people have an ethical/religious objection
• Development of stem cell therapies are slow, expensive and difficult
• Adult stem cells infected with viruses could transfer injections to patients
• If donor stem cells do not have similar genetic makeup to the patient, an immune response could be triggered