Please check the examination details below before entering your candidate information
Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel International Advanced Level
Tuesday 14 January 2025
Afternoon (Time: 1 hour 45 minutes) Paper
reference WBI15/01
Biology
International Advanced Level
UNIT 5: Respiration, Internal Environment,
Coordination and Gene Technology
You must have: Total Marks
Scientific article (enclosed), scientific calculator, ruler, HB pencil
Instructions
•• Use black ink or ball‑point pen.
Fill in the boxes at the top of this page with your name,
centre number and candidate number.
•• Answer all questions.
Answer the questions in the spaces provided
– there may be more space than you need.
Information
•• The total mark for this paper is 90.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• Into the question labelled with an asterisk (*), marks will be awarded for your ability
structure your answer logically, showing how the points that you make are
related or follow on from each other where appropriate.
Advice
•• Read each question carefully before you start to answer it.
Try to answer every question.
• Check your answers if you have time at the end.
Turn over
P78446A
©2025 Pearson Education Ltd.
H:1/1/1/1/1/
*P78446A0132*
, Answer ALL questions.
Write your answers in the spaces provided.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
Some questions must be answered with a cross in a box . If you change your mind about an
answer, put a line through the box and then mark your new answer with a cross .
1 Proteins are one type of biological molecule.
(a) (i) Complete the diagram to show the molecules formed when these
two amino acids join together.
(2)
R H R H
HO C C N H + HO C C N H
O H O H
(ii) Which is the type of reaction that joins these two molecules together?
(1)
A condensation
B decarboxylation
C hydrolysis
D phosphorylation
2
*P78446A0232*
, (b) Excess proteins are broken down into amino acids.
Describe what happens to these amino acids.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
(3)
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
(Total for Question 1 = 6 marks)
3
*P78446A0332* Turn over
, 2 The diagram shows a cross‑section of the human brain.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
(Source: © Rendix Alextian / Shutterstock)
(a) Label the diagram to show the locations of the pituitary gland (P),
cerebellum (C) and hypothalamus (H).
(3)
(b) Complete the table to show one function of each part of the brain.
(3)
Part of the brain Function
hypothalamus
medulla oblongata
pituitary gland
(Total for Question 2 = 6 marks)
4
*P78446A0432*
Candidate surname Other names
Centre Number Candidate Number
Pearson Edexcel International Advanced Level
Tuesday 14 January 2025
Afternoon (Time: 1 hour 45 minutes) Paper
reference WBI15/01
Biology
International Advanced Level
UNIT 5: Respiration, Internal Environment,
Coordination and Gene Technology
You must have: Total Marks
Scientific article (enclosed), scientific calculator, ruler, HB pencil
Instructions
•• Use black ink or ball‑point pen.
Fill in the boxes at the top of this page with your name,
centre number and candidate number.
•• Answer all questions.
Answer the questions in the spaces provided
– there may be more space than you need.
Information
•• The total mark for this paper is 90.
The marks for each question are shown in brackets
– use this as a guide as to how much time to spend on each question.
• Into the question labelled with an asterisk (*), marks will be awarded for your ability
structure your answer logically, showing how the points that you make are
related or follow on from each other where appropriate.
Advice
•• Read each question carefully before you start to answer it.
Try to answer every question.
• Check your answers if you have time at the end.
Turn over
P78446A
©2025 Pearson Education Ltd.
H:1/1/1/1/1/
*P78446A0132*
, Answer ALL questions.
Write your answers in the spaces provided.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
Some questions must be answered with a cross in a box . If you change your mind about an
answer, put a line through the box and then mark your new answer with a cross .
1 Proteins are one type of biological molecule.
(a) (i) Complete the diagram to show the molecules formed when these
two amino acids join together.
(2)
R H R H
HO C C N H + HO C C N H
O H O H
(ii) Which is the type of reaction that joins these two molecules together?
(1)
A condensation
B decarboxylation
C hydrolysis
D phosphorylation
2
*P78446A0232*
, (b) Excess proteins are broken down into amino acids.
Describe what happens to these amino acids.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
(3)
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .. .. .. .. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................................................................................................................ ................ . . . . . . . . . . . . . . . . . . . .
(Total for Question 1 = 6 marks)
3
*P78446A0332* Turn over
, 2 The diagram shows a cross‑section of the human brain.
DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA DO NOT WRITE IN THIS AREA
(Source: © Rendix Alextian / Shutterstock)
(a) Label the diagram to show the locations of the pituitary gland (P),
cerebellum (C) and hypothalamus (H).
(3)
(b) Complete the table to show one function of each part of the brain.
(3)
Part of the brain Function
hypothalamus
medulla oblongata
pituitary gland
(Total for Question 2 = 6 marks)
4
*P78446A0432*
