Cell Division And Differentiation 1st Topic Test

Question 1

How many chromosomes are in a fertilised human egg?

Answer 1

46 (23 pairs)

Question 2

When stem cells become specialised, what is the process called?

Answer 2

Differentiation

Question 3

Mitosis is when

Answer 3

The nucleus divides, two nuclei form and the chromosomes move apart

Question 4

Why are stem cells from human embryos more useful than stem cells from adults?

Answer 4

Stem cells from human embryos can differentiate into more types of cells. Human stem cells can only differentiate into blood cells

Question 5

Going from a fertilised egg to stem cells, what two parts would be found in all of the cells during the process.

Answer 5

Cell membrane, cytoplasm

Question 6

Why are some scientists medically concerned about the use of stem cells?

Answer 6

They can cause viral infection eg cancer

Question 7

Other than religious beliefs, what is an ethical concern about embryonic stem cell use?

Answer 7

People think that embryos have life so we are killing it.

Question 8

Why do sperm cells need a lot of mitochondria?

Answer 8

They need a lot of energy to swim

Question 9

How does a chromosome become two strands

Answer 9

The DNA copies itself

Question 10

Explain why each chromosome needs to become two strands before the cell divides

Answer 10

So the daughter cells are genetically identical to the mother cell.

Question 11

Where is a place in a plant where stem cells are found.

Answer 11

Meristems

Question 12

Describe what happens in each of the three stages of the cell cycle.

Answer 12

• Firstly, during interphase, the cell duplicates its chromosomes and subecellular structures like mitochondria and ribosomes.
• Secondly, the chromosomes are pulled to each end of the cell (mitosis) in preparation to split.
• Thirdly, the cell then divides into two (cytokinesis) which helps repair damaged cells or is used for growth/development.

Question 13

What are two advantages and disadvantages of therapeutic cloning in medical treatments.

Answer 13

• Advantage 1: Helps treat diseases due to the identical embryonic stem cells
• Advantage 2: Less chance of rejection
• Disadvantage 1: Can cause viral infections
• Disadvantage 2: Ethically questionable as the stem cell can’t consent even though the embryo may be living