Paper 2 Questions + Answers

Question 1

Does the picture show the cell in the anaphase stage of mitosis,why?
2 marks

Answer 1

The spindle fibres have pulled the individual chromatids making up the chromosomes apart. To opposite poles.
V shape shows that the sister chromatids have been pulled apart at their centromeres.

Question 2

“Push down hard on the cover slip, but do not push the cover slip sideways.”
Explain why she was given this instruction.
[2 marks]

Answer 2

Push hard to spread the tissue.

Don’t push sideways to avoid rolling cells together and breaking chromosomes.

Question 3

Endopeptidases and exopeptidases are involved in the hydrolysis of proteins.
Name the other type of enzyme required for the complete hydrolysis of proteins to amino acids. [1 mark]

Answer 3

Dipeptidases

Question 4

Suggest and explain why the combined actions of endopeptidases and exopeptidases are more efficient than exopeptidases on their own. [2 marks]

Answer 4

Endopeptidases hydrolyse peptide bonds.
Exopeptidase’s remove amino acids at ends.
More ends or increase in surface area.

Question 5

The addition of a respiratory inhibitor stops the absorption of amino acids.
Explain why.
[3 marks]

Answer 5

1) Less ATP produced. No active transport.
2) Sodium ions not moved in or out of the cell.
3) No concentration gradient for sodium to move into cell with amino acid.