Questions and Answers
01 . 1) The scientist concluded that the cells in flask G took up sodium ions by active
transport. Explain how the information given supports this conclusion.
[4 marks] Correct Ans-1. Uptake in flask G much greater than in flask F;
2. Showing use of ATP in flask G;
3. Sodium ion concentration in flask G falls to
zero;
4. Showing uptake against a concentration
gradient;
02 . 2) The curve for flask F levelled off after 20 minutes. Explain why.
[2 marks] Correct Ans-1. (Uptake of sodium ions occurring by) facilitated
diffusion;
2. Equilibrium reached/sodium ion concentrations
, AS Biology (7401/2) Paper 2 Specimen 2024/25-
Questions and Answers
in solution and in cells the same;
03 . 1) Figure 3 represents one process that occurs during protein synthesis.
Name the process shown.
[1 mark] Correct Ans-Translation;
03 . 2) Identify the molecule labelled Q.
[1 mark] Correct Ans-Transfer RNA/tRNA;
03 . 3) In Figure 3, the first codon is AUG. Give the base sequence of:
[2 marks] Correct Ans-TAC;
UAC;
, AS Biology (7401/2) Paper 2 Specimen 2024/25-
Questions and Answers
03 . 4) Table 1 shows the base triplets that code for two amino acids.
Aspartic acid and proline are both amino acids. Describe how two amino acids differ
from one another. You may use a diagram to help your description.
[1 mark] Correct Ans-Have different R group;
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] Correct Ans-1. Push hard - spread/squash tissue;
2. Not push sideways - avoid rolling cells