Date:
A-level Mark Grade
AQA
BIOLOGY
Materials
For this paper you must have:
Ruler
Instructions
All working must be shown
Information
, (a) A.student.measured.the.rate.of.aerobic.respiration.of.a.woodlouse.using.the.apparatus
1. .shown.in.the.diagram.
(i) The.student.closed.the.tap..After.thirty.minutes.the.drop.of.coloured.liquid.had.moved
.to.the.left..Explain.why.the.drop.of.coloured.liquid.moved.to.the.left.
(3)
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, (ii) What.measurements.should.the.student.have.taken.to.calculate.the.rate.of.aerobic
.respiration.in.mm3.of.oxygen.g–1.h–1?
(3)
(b) DNP.inhibits.respiration.by.preventing.a.proton.gradient.being.maintained.across.membr
anes..When.DNP.was.added.to.isolated.mitochondria.the.following.changes.were.observ
ed
• less.ATP.was.produced
• more.heat.was.produced
• the.uptake.of.oxygen.remained.constant.
Explain.how.DNP.caused.these.changes.
(3)
(Total.9.marks)
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