AM Textbook
A-LEVEL
Biology
Paper 2
Mark
scheme
7402
June 2017
Version: 1.0 Final
about:bl 1/
,10/16/24, 10:58 AQA 7402 2 W MS Jun17 - A-Level CGPAQA Biology
AM Textbook
Mark schemes are prepared by the Lead Assessment Writer and considered, together
with the relevant questions, by a panel of subject teachers. This mark scheme includes
any amendments made at the standardisation events which all associates participate in
and is the scheme which was used by them in this examination. The standardisation
process ensures that the mark scheme covers the students’ responses to questions and
that every associate understands and applies it in the same correct way. As preparation
for standardisation each associate analyses a number of students’ scripts. Alternative
answers not already covered by the mark scheme are discussed and legislated for. If,
after the standardisation process, associates encounter unusual answers which have not
been raised they are required to refer these to the Lead Assessment Writer.
It must be stressed that a mark scheme is a working document, in many cases further
developed and expanded on the basis of students’ reactions to a particular paper.
Assumptions about future mark schemes on the basis of one year’s document should
be avoided; whilst the guiding principles of assessment remain constant, details will
change, depending on the content of a particular examination paper.
Further copies of this mark scheme are available from aqa.org.uk
Copyright © 2017 AQA and its licensors. All rights reserved.
AQA retains the copyright on all its publications. However, registered schools/colleges for AQA are permitted to copy
material from this booklet for their own internal use, with the following important exception: AQA cannot give permission to
schools/colleges to photocopy any material that is acknowledged to a third party even for internal use within the
centre.
about:bl 2/
, 10/16/24, 10:58 AQA 7402 2 W MS Jun17 - A-Level CGPAQA Biology
AM Textbook
MARK SCHEME – A-LEVEL BIOLOGY – 7407/2 – JUNE
2017
Question Marking Guidance Mark Comments
01.1 1. Chemoreceptors detect rise in
+ 4 1. Ignore:
CO2/H /acidity/carbonic acid/fall in
location of
pH OR receptors.
1. Ignore:
Baro/pressure receptors detect rise in chemoreceptors
blood pressure; detect oxygen.
2. Send impulses to cardiac
centre/medulla; 2 and 3.
Accept: action
3. More impulses to SAN; potentials.
4. By sympathetic (nervous
system for 2. Reject:
chemoreceptors/CO2) ‘messages’,
‘signals’, ‘an
OR impulse’ or an
By parasympathetic (nervous system ‘action potential’.
for baro/pressure receptors/blood
pressure); 3. Ignore:
messages’,
‘signals’, ‘an
impulse’ or an
‘action potential’
as emphasis here
is on increase in
frequency.
01.2 1. Less/no malonyl-CoA;
3 1. ‘Inhibition of
2. (More) fatty acids malonyl-CoA’ on
transported/moved into its own is not
mitochondria; enough but accept
production of
3. Respiration/oxidation of fatty acids
malonyl-CoA is
provides ATP;
inhibited.
2. Accept:
‘transport of
fatty acids into
mitochondria is
not inhibited’.
2. Ignore: method
of entry.
3. Accept: for
respiration any
stage of aerobic
respiration
e.g. Krebs
(cycle), link
(reaction) etc.
3. Reject:
production of
energy, but accept
production of
energy in the form
of ATP.
about:bl 3/