Centre Candidate
Surname
Number Number
First name(s) 2
GCE A LEVEL
S25-A400U30-1
A400U30-1
WEDNESDAY, 18 JUNE 2025 – MORNING
BIOLOGY – A level component 3
Requirements for Life
2 hours For Examiner’s use only
Maximum Mark
Question
Mark Awarded
1. 10
2. 12
A 40 0U3 01
3. 20
01
Section A
4. 14
5. 15
ADDITIONAL MATERIALS
6. 9
A calculator and a ruler.
Section B Option 20
Total 100
INSTRUCTIONS TO CANDIDATES
Use black ink or black ball-point pen. Do not use gel pen or correction fluid.
Write your name, centre number and candidate number in the spaces at the top of this page.
Answer all questions.
Write your answers in the spaces provided in this booklet. If you run out of space, use the
additional page(s) at the back of the booklet, taking care to number the question(s) correctly.
INFORMATION FOR CANDIDATES
This paper is in 2 sections, A and B.
Section A: 80 marks. Answer all questions. You are advised to spend about 1 hour 35 minutes on
this section.
Section B: Options; 20 marks. Answer one option only. You are advised to spend about
25 minutes on this section.
The number of marks is given in brackets at the end of each question or part-question.
The assessment of the quality of extended response (QER) will take place in question 6.
The quality of written communication will affect the awarding of marks.
JUN25A400U30101 © WJEC CBAC Ltd. BE/GR*(X24-A400U30-1)
, 2
Examiner
only
Answer all questions.
1. The mammalian reflex arc consists of several components for sensing and responding to the
environment. Image 1.1 shows the reflex arc involved when a heat source is touched by a
finger.
Image 1.1
C
F
E B
G
D
A
(a) Use letters A to G from Image 1.1 to complete the table. [2]
Component of reflex arc Letter
Coordinator (spinal cord) B
Effector ..................
Motor neurone ..................
Receptor ..................
Response E
Sensory neurone ..................
Stimulus A
02 © WJEC CBAC Ltd. (A400U30-1)
, 3
Examiner
only
(b)
Impulses are transferred along both sensory and motor neurones as a wave of action
potentials.
Describe how the movement of ions generates an action potential. [3]
A 40 0U3 01
03
03 © WJEC CBAC Ltd. (A400U30-1) Turn over.
, 4
Examiner
only
(c) Nerve nets are found in cnidarians (for example, Hydra) and are different from the
nervous systems of vertebrates. Image 1.2 shows a nerve net in Hydra and the nervous
system of a human.
Image 1.2
Hydra Human
nerve net
Use your own knowledgeDiagram
(i) not drawn provided
and the information to scale in Image 1.2 to give three
differences between the nerve net of Hydra and the nervous system in a human.
[3]
Hydra Human
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
04 © WJEC CBAC Ltd. (A400U30-1)
Surname
Number Number
First name(s) 2
GCE A LEVEL
S25-A400U30-1
A400U30-1
WEDNESDAY, 18 JUNE 2025 – MORNING
BIOLOGY – A level component 3
Requirements for Life
2 hours For Examiner’s use only
Maximum Mark
Question
Mark Awarded
1. 10
2. 12
A 40 0U3 01
3. 20
01
Section A
4. 14
5. 15
ADDITIONAL MATERIALS
6. 9
A calculator and a ruler.
Section B Option 20
Total 100
INSTRUCTIONS TO CANDIDATES
Use black ink or black ball-point pen. Do not use gel pen or correction fluid.
Write your name, centre number and candidate number in the spaces at the top of this page.
Answer all questions.
Write your answers in the spaces provided in this booklet. If you run out of space, use the
additional page(s) at the back of the booklet, taking care to number the question(s) correctly.
INFORMATION FOR CANDIDATES
This paper is in 2 sections, A and B.
Section A: 80 marks. Answer all questions. You are advised to spend about 1 hour 35 minutes on
this section.
Section B: Options; 20 marks. Answer one option only. You are advised to spend about
25 minutes on this section.
The number of marks is given in brackets at the end of each question or part-question.
The assessment of the quality of extended response (QER) will take place in question 6.
The quality of written communication will affect the awarding of marks.
JUN25A400U30101 © WJEC CBAC Ltd. BE/GR*(X24-A400U30-1)
, 2
Examiner
only
Answer all questions.
1. The mammalian reflex arc consists of several components for sensing and responding to the
environment. Image 1.1 shows the reflex arc involved when a heat source is touched by a
finger.
Image 1.1
C
F
E B
G
D
A
(a) Use letters A to G from Image 1.1 to complete the table. [2]
Component of reflex arc Letter
Coordinator (spinal cord) B
Effector ..................
Motor neurone ..................
Receptor ..................
Response E
Sensory neurone ..................
Stimulus A
02 © WJEC CBAC Ltd. (A400U30-1)
, 3
Examiner
only
(b)
Impulses are transferred along both sensory and motor neurones as a wave of action
potentials.
Describe how the movement of ions generates an action potential. [3]
A 40 0U3 01
03
03 © WJEC CBAC Ltd. (A400U30-1) Turn over.
, 4
Examiner
only
(c) Nerve nets are found in cnidarians (for example, Hydra) and are different from the
nervous systems of vertebrates. Image 1.2 shows a nerve net in Hydra and the nervous
system of a human.
Image 1.2
Hydra Human
nerve net
Use your own knowledgeDiagram
(i) not drawn provided
and the information to scale in Image 1.2 to give three
differences between the nerve net of Hydra and the nervous system in a human.
[3]
Hydra Human
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
........................................................................................ ........................................................................................
04 © WJEC CBAC Ltd. (A400U30-1)
