Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Gas Exchange
Mark Scheme
Level
IGCSE
Subject
Biology
Exam Board
Edexcel
Topic
Structure and Functions in Living Organisms
Sub-Topic
Gas Exchange
Booklet-Module
Mark Scheme-Double Award (Paper 1B)
Time Allowed:
53 minutes
Score:
/44
Percentage:
/100
Grade Boundaries:
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Question
number
2 (a)
(i)
Answer
Notes
correct reference to oxygen + carbon dioxide;
(ii) 1.. l
2.. th
1
ge (surface) area;
/ eq;
3.. b od supply / capillaries;
4.. perm
ble;
Marks
max 3
Ignore thin cell
walls
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Question
number
2 (b)
(i)
Answer
S – scale linear;
L – straight and through points;
A – correct way;
A – labelled (breathing rate) per minute/
(breaths) per minute + OC;
P – points plotted accurately;
(ii)
breathing rate higher (in warmer water) / mouth
opens more often (at higher temperature) / eq;
(iii)
different size may need different amount of
oxygen / bigger fish may need more oxygen /
different size may have different breathing rates /
eq;
(iv) 1..
ecies / type / eq;
2.. ag
3.. ge
4..
Notes
Marks
5
Ignore
extrapolation
1
Ignore idea of
fair test
1
Ignore time /
size of fish /
type of tank /
food
max 2
er;
ygen level / volume of water / size of tank /
number of fish / source of water / light;
Total
13
Marks
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Question
number
3 (a) (i)
(ii)
(b)
(c)
(d)
Answer
Notes
1
lungs;
diaphragm;
Marks
allow phonetic spelling
1
(iii) trachea / windpipe;
eg dyaphram
1
(iv) bronchus / bronchi;
ignore bronchioles /
ignore right and left
1
ignore vacuum
ignore area
3
allow converse
2
1 allow if implied
2 ignore measure
breathing - need method
3 is measure rate mark
not exercise quantified
5 allow average
4
balloons inflate / air into balloons / eq;
volume (in model) increases / more space (in model) /
eq;
pressure decreases / eq;
(no) ribs / ribcage;
(no) (intercostal) muscles;
(no) pleural membranes;
(no) movement (of chest) / up and out / expansion;
1 rest and exercise / range of exercise /
jog and run / eq;
2 (how) count breaths / how many breaths /
amount of breaths / volume / eq;
3 for time / seconds / minutes / eq;
4 quantification of exercise / jog for 5 minutes /
do 10 press ups;
5 repeat (for reliability);
Total
13
Save My Exams! – The Home of Revision
For more awesome GCSE and A level resources, visit us at www.savemyexams.co.uk/
Ouesttin
number
4
<•>
(I)
250000;
Answer
Notes
Hao1cs
1
32;: alow one mark for 80 000 In working
(b)
1. rare/random;
2. change/damage / eq;
3. DNA/gene/ allele/ genetk code/ eq;
(c)
1. less surface area;
2. slower dtffuslOn/less d1ffusk>n/ less gas exchange;
3. less oxygen/ less carbon dk>xlde;
(d)
2
random change rn cells =2
Ignore less room
2
allow converse for X
1. bk>cked / narrowed/ clogged/ eq;
5
2. com,wy artecv·
3. c:lo t;
4. fat/ cholesterol;
S. less blood to heart·
6. less oxygen/ less oxygenated;
7. JIWSt1e. (cells);
8. less respiration/anaerobk respiration;
9. lactie ac:td/ an gina;
10. heart attack/heart stoos/ cardiac arrest/_,.
2
(Total for Question 4 = 12 marlcs)