AS BIOLOGY (7401/2) PAPER 2
SPECIMEN. EXAM QUESTIONS AND
ANSWERS. VERIFIED 2025/2026.
01 . 1) A student investigated mitosis in the tissue from an onion root tip.
The student prepared a temporary mount of the onion tissue on a glass slide. She
covered the tissue with a cover slip. She was then given the following instruction.
"Push down hard on the cover slip, but do not push the cover slip sideways."
Explain why she was given this instruction.
[2 marks] - ANS 1. Push hard - spread/squash tissue;
2. Not push sideways - avoid rolling cells
together/breaking chromosomes;
01 . 2) The student concluded that the cell in Figure 1 was in the anaphase stage of mitosis.
Was she correct? Give two reasons for your answer.
[2 marks] - ANS No (no mark)
Yes (no mark)
1. Chromosomes/chromatids are (in two groups)
at poles of spindle/at ends of spindle;
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, 2. V-shape shows that (sister) chromatids have
been pulled apart at their centromeres/that
centromeres of (sister) chromatids have been
pulled apart;
01 . 3) The student counted the number of cells she observed in each stage of mitosis.
Of the 200 cells she counted, only six were in anaphase.
One cell cycle of onion root tissue takes 16 hours. Calculate how many minutes these
cells spend in anaphase.
Show your working.
[2 marks] - ANS 28.;
02 . 2) A scientist investigated the uptake of sodium ions by animal tissue.
To do this, he:
• used two flasks, F and G
• put equal masses of animal tissue into each flask
• added equal volumes of a solution containing sodium ions to each flask
• added to flask F a solution of a substance that prevents the formation of ATP by
cells
• measured the concentration of sodium ions remaining in the solution in each
flask.
Figure 2 shows his results.
Calculate the rate of uptake of sodium ions by the tissue in flask G during the first
20 minutes of this investigation.
[1 mark] - ANS 0.22;
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
SPECIMEN. EXAM QUESTIONS AND
ANSWERS. VERIFIED 2025/2026.
01 . 1) A student investigated mitosis in the tissue from an onion root tip.
The student prepared a temporary mount of the onion tissue on a glass slide. She
covered the tissue with a cover slip. She was then given the following instruction.
"Push down hard on the cover slip, but do not push the cover slip sideways."
Explain why she was given this instruction.
[2 marks] - ANS 1. Push hard - spread/squash tissue;
2. Not push sideways - avoid rolling cells
together/breaking chromosomes;
01 . 2) The student concluded that the cell in Figure 1 was in the anaphase stage of mitosis.
Was she correct? Give two reasons for your answer.
[2 marks] - ANS No (no mark)
Yes (no mark)
1. Chromosomes/chromatids are (in two groups)
at poles of spindle/at ends of spindle;
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, 2. V-shape shows that (sister) chromatids have
been pulled apart at their centromeres/that
centromeres of (sister) chromatids have been
pulled apart;
01 . 3) The student counted the number of cells she observed in each stage of mitosis.
Of the 200 cells she counted, only six were in anaphase.
One cell cycle of onion root tissue takes 16 hours. Calculate how many minutes these
cells spend in anaphase.
Show your working.
[2 marks] - ANS 28.;
02 . 2) A scientist investigated the uptake of sodium ions by animal tissue.
To do this, he:
• used two flasks, F and G
• put equal masses of animal tissue into each flask
• added equal volumes of a solution containing sodium ions to each flask
• added to flask F a solution of a substance that prevents the formation of ATP by
cells
• measured the concentration of sodium ions remaining in the solution in each
flask.
Figure 2 shows his results.
Calculate the rate of uptake of sodium ions by the tissue in flask G during the first
20 minutes of this investigation.
[1 mark] - ANS 0.22;
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
