Biology Paper 2 Theory 5090-21 May June 2025 Past Paper Comprehensive Revision Guide 2025/ 2026

Biology Paper 2 Theory 5090-21 May-June 2025
Biology
PAPER.pdf
Paper 2 Theory 5090-21 May-June 2025Biology
PAPER.pdf
Paper 2 Theory 5090-21 May-June 2025 PAPER
* 0000800000001 *



,










,




Cambridge O Level

¬OŠ. 4mHuOªEŠ_z6€W
¬Aoz\¢ŒqgnyR‡G-‚¦‚
¥5u•5U 5 • Ue•eU
* 1 9 3 1 6 8 6 9 5 1 *




BIOLOGY 5090/21
Paper 2 Theory May/June 2025
1 hour 45 minutes

You must answer on the question paper.

No additional materials are needed.

INSTRUCTIONS
● Answer all questions.
● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs.
● Write your name, centre number and candidate number in the boxes at the top of the page.
● Write your answer to each question in the space provided.
● Do not use an erasable pen or correction fluid.
● Do not write on any bar codes.
● You may use a calculator.
● You should show all your working and use appropriate units.


INFORMATION
● The total mark for this paper is 80.
● The number of marks for each question or part question is shown in brackets [ ].




This document has 16 pages. Any blank pages are indicated.


DC (SL/FC) 342041/4
© UCLES 2025 [Turn over



Biology Paper 2 Theory 5090-21 May-June 2025 PAPER.pdf 5/29/2026 Biology Paper 2 Theory 5090-21 May-June 2025 PAPER.pdf

,Biology Paper 2 Theory 5090-21 May-June 2025
Biology
PAPER.pdf
Paper 2 Theory 5090-21 May-June 2025Biology
PAPER.pdf
Paper 2 Theory 5090-21 May-June 2025 PAPER
* 0000800000002 *




DO NOT WRITE IN THIS MARGIN
2
,










,

Answer all questions.

Write your answers in the spaces provided.

1 (a) Large molecules in cells are made from smaller molecules.

Complete Table 1.1 to show which small molecules make up each large molecule.

Choose the small molecules from this list.

amino acids fatty acids glucose glycerol nucleotides




DO NOT WRITE IN THIS MARGIN
Table 1.1

large molecule small molecules
protein
cellulose
lipid
[3]

(b) DNA is found in the nucleus of each cell.




DO NOT WRITE IN THIS MARGIN
Put a tick (✓) next to any statements that correctly describe the structure of DNA.

A DNA molecule has four strands coiled together to form a helix.
Each strand is made up of a chain of nucleotides.
Each nucleotide contains a base, a sugar and an amino acid.
The bases always pair up in the same way, A with T, and C with G.
Bonds between sugar molecules hold the strands together.
[2]




DO NOT WRITE IN THIS MARGIN
(c) Explain how the sequence of bases in a DNA molecule controls how a cell functions.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................
DO NOT WRITE IN THIS MARGIN




............................................................................................................................................. [3]

[Total: 8]




ĬÍĊ®Ġ´íÈõÏĪÅĊÞü¸þ×
© UCLES 2025 ĬÁíùÙĦĀėÐăÿ­¯­ýºĞĂ 5090/21/M/J/25
ĥĥĥĕõµÅÕµÕÕÅąĕÅÕąÕ



Biology Paper 2 Theory 5090-21 May-June 2025 PAPER.pdf 5/29/2026 Biology Paper 2 Theory 5090-21 May-June 2025 PAPER.pdf

, Biology Paper 2 Theory 5090-21 May-June 2025
Biology
PAPER.pdf
Paper 2 Theory 5090-21 May-June 2025Biology
PAPER.pdf
Paper 2 Theory 5090-21 May-June 2025 PAPER
* 0000800000003 *
DO NOT WRITE IN THIS MARGIN



3
,










,

2 (a) Fig. 2.1 shows a food web from a pond.




snake


hawk
DO NOT WRITE IN THIS MARGIN




frog
water
shrew


freshwater insect
snail larva



water weed alga
DO NOT WRITE IN THIS MARGIN




Fig. 2.1

(i) State the source of energy for this food web.

..................................................................................................................................... [1]

(ii) Complete Table 2.1 by writing the number of different organisms in this food web that fit
each description.

The first one has been done for you.

Table 2.1
DO NOT WRITE IN THIS MARGIN




number of different
description
organisms
producers 2
secondary consumers
carnivores
[2]

(iii) The hawk feeds at two different trophic levels.
Use Fig. 2.1 to explain this statement.
DO NOT WRITE IN THIS MARGIN




...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

..................................................................................................................................... [2]
ĬÏĊ®Ġ´íÈõÏĪÅĊÞú¸þ×
© UCLES 2025 ĬÁîúÑĤĄħéõòüīÅÙºĎĂ
ĥĥĕÕµÕåµååąÅąõåĕĕÕ
5090/21/M/J/25 [Turn over

Biology Paper 2 Theory 5090-21 May-June 2025 PAPER.pdf 5/29/2026 Biology Paper 2 Theory 5090-21 May-June 2025 PAPER.pdf