State which structure is formed in animal cells by the pinching of the plasma membrane during cytokinesis.
[1 mark]
The drawings below show a cell during different stages of mitosis.
List the stages P, Q, R, S and T in the correct sequence.
[3 marks]
Cell M contains 74 chromosomes. It divides by mitosis.
State how many chromosomes the daughter cells will contain.
[1 mark]
State which proteins are used to control the cell cycle.
[1 mark]
The diagram below represents the different phases of the cell cycle.
State all the letters in the diagram that represent the phases of interphase.
[1 mark]
The tumour suppressor gene TP53 codes for a protein that interrupts the cell cycle if there is any damage to the DNA and prevents the copying of damaged DNA.
State which stage of the cell cycle this gene would interrupt.
[1 mark]
The diagram below shows two different stages of mitosis.
Identify structures M, N and O.
[3 marks]
List three reasons why cells will undergo mitosis.
[3 marks]
State the process that occurs during prophase that enables chromosomes to condense.
[1 mark]
The diagram below shows some grasshopper cells.
State the stages of the cell cycle shown by X and Y.
[2 marks]
Outline the events occurring during the stage shown as Z in part (a).
[3 marks]
The diagram below shows onion cells from the root tip.
Calculate the mitotic index for this root tip.
[2 marks]
Doctors use the mitotic index when examining tumours.
Suggest what a high mitotic index would indicate to a doctor.
[1 mark]
One mark is available for clarity of communication throughout this question.
Outline how the role of cyclins in the cell cycle was discovered.
[3 marks]
Budding yeast cells complete a cell cycle in 90 minutes.
Outline the stages in the cell cycle that result in the development of new yeast cells.
[6 marks]
Compare and contrast cell division of prokaryotic and eukaryotic cells.
[6 marks]
