Mark Scheme (Results)

March 2013

GCSE Biology
5BI1H/01
Edexcel and BTEC Qualifications

Edexcel and BTEC qualifications come from Pearson, the world’s leading learning
company. We provide a wide range of qualifications including academic, vocational,
occupational and specific programmes for employers. For further information visit our
qualifications websites at www.edexcel.com or www.btec.co.uk for our BTEC
qualifications.
Alternatively, you can get in touch with us using the details on our contact us page at
www.edexcel.com/contactus.

If you have any subject specific questions about this specification that require the help of
a subject specialist, you can speak directly to the subject team at Pearson.
Their contact details can be found on this link: www.edexcel.com/teachingservices.

You can also use our online Ask the Expert service at www.edexcel.com/ask. You will
need an Edexcel username and password to access this service.

Pearson: helping people progress, everywhere

Our aim is to help everyone progress in their lives through education. We believe in
every kind of learning, for all kinds of people, wherever they are in the world. We’ve
been involved in education for over 150 years, and by working across 70 countries, in
100 languages, we have built an international reputation for our commitment to high
standards and raising achievement through innovation in education. Find out more about
how we can help you and your students at: www.pearson.com/uk

March 2013
Publications Code UG035089
All the material in this publication is copyright
© Pearson Education Ltd 2013
Question Answer Acceptable answers Mark
Number

1a(i) A – nucleus (1) A – cell body

B – myelin (sheath) (1) B – Schwann cell / fatty layer

(3)
C – axon (1)

Question Answer Acceptable answers Mark

Number

1a(ii) C - effectors (1)

Question Answer Acceptable answers Mark

Number
(67 + 60+ 62) = 189 (1) Two marks for correct bald
1b(i) answer
(189) / 3 ans = 63 (ms) (1)
ECF for incorrect calculation (2)
carried out correctly.

Question Answer Acceptable answers Mark

Number
An explanation to include the Reject stimulant (no further
1b(ii) following points: marks awarded)

Ignore references to CNS

alcohol is a depressant (1) accept sedative

slows down the activity of the accept: slows reactions /

brain (1) reactions take longer / reaction
time increases
(slows down) neurotransmission (2)
(1)

(slows down) transmission at the

synapse (1)

Total for question 1 = 8 marks

Question Answer Acceptable answers Mark
Number

2a(i) Genus – Geospiza accept geospiza

Species -conirostris accept Conirostris (2)

Question Answer Acceptable answers Mark

Number
A suggestion including two of the
2a(ii) following:

• (different beak eat different foods

sizes/adapted) enable accept comparison between 2
different finches to feed on beaks and food source
different food types (1)

• less competition between

species (1)
(2)

more species are able to co-exist

(1)

Question Answer Acceptable answers Mark

Number

2a(iii) B 6 geographic isolation (1)

Question Answer Acceptable answers Mark
Number
A suggestion linking three
2b of the following points:

• variation between species/

beak sizes/ shapes (1)

• due to mutation(1)

• competition for resources

(1)

• survival of the fittest

/those best adapted to the
environment survived (1)

• those who survive pass

their genes/characteristics
onto their offspring (1)
(3)
• natural selection (1)

Total for question 2 – 8 marks

Question Answer Acceptable answers Mark
Number

3a(i) C 6 nitrification (1)

Question Answer Acceptable answers Mark

Number
an explanation to include the Ignore references to use as
3a(ii) following points food (plants do not feed)

• used to make protein (1) accept amino acids/ chlorophyll

/DNA

• for growth (1) ignore references to

photosynthesis / respiration
(2)

Question Answer Acceptable answers Mark

Number
A description linking four of the
3a(iii) following points

(nitrates) leach/flow into water accept fertilisers for nitrates

(1)

algae and small plants grow

rapidly /algal bloom (1)

underwater plants cannot

photosynthesise (1)

(lack of photosynthesis /
sunlight) causes plants to die (1)

decomposers / (decomposing)
bacteria break down the dead
material / plants (1)

these bacteria use up oxygen

during respiration(1)
(4)
Question Answer Acceptable answers Mark
Number
An explanation to include three
3b of the following points

bacteria use nitrogen / nitrogen

fixing bacteria (1)

make ammonia / ammonium /

nitrogen compounds /nitrates for
use by plants (1)

bacteria protected (within the

root nodule) (1)

bacteria obtain chemical Ignore food/nutrients

substances / glucose / sugar
from the plant (1)
reject parasitism
this is called a mutualism /
symbiosis(1) (3)

Total for question 3 = 10 marks

Question Answer Acceptable answers Mark
Number
A description including the
4(a)(i) following points:

• as mean mass increases so accept positive correlation

does the percentage of ORA
population with type 2
diabetes (1)

• correct readings from the

graph to illustrate the
comparative point (1)
(2)

Question Answer Acceptable answers Mark

Number
A suggestion linking two of the
4(a)(ii) following:

• increasing body mass

leads to over weight /
obesity

• don’t respond to insulin /

reference to insulin (2)
resistance

Question Answer Acceptable answers Mark

Number
Calculation Two marks for correct bald
4(b)(i) answer
(1.7 x 1.7) = 2.89 (1)

78 / 2.89
Ecf for incorrect numbers but
= 27 (1) correct calculation

26.98 / 26.9 (2)

Accept continued decimal places
Question Answer Acceptable answers Mark
Number

4(b)(ii) C 6 overweight (1)

Question Answer Acceptable answers Mark

Number
A description linking three of the correct spelling of glycogen and
4(c) following: glucagon only

• glucagon is released (1) No mark for glucagon is injected

• from the pancreas (1)

• glycogen to glucose (1) Ignore references to glucagon

turning into glucose
• in the liver / muscle
cells(1)

• which acts to raise blood

glucose levels (1) (3)

Total for question 4 – 10 marks

Question Answer Acceptable answers Mark
Number
D 6 positive phototropism
5(a)(i) (1)

Question Answer Acceptable answers Mark

Number
An explanation to include the
5(a)(ii) following linked points

(auxins) move to the shaded side accept move to the side opposite
of a shoot (1) the light

causing cells on the shaded side accept get longer for elongate
to elongate (1) Ignore references to cell division
(2)

Question Answer Acceptable answers Mark

Number
5(b)(i) there is an increase in the % of Ignore positive effect
bananas that ripen as the
ethylene concentration increases (1)

Question Answer Acceptable answers Mark

Number
An explanation to include two of
5(b)(ii) the following points

• concentration of ethylene
to use is 3% (1)

• would be more expensive

to increase the ethylene
concentration above 3%

• when there is no added

ripening benefits past
3%(1)

• below 3% not all bananas

are ripe (1) Do not credit ideas related to (2)
longer shelf life as the question
asks about ripening
Question Indicative Content Mark
Number
QWC *5(c) A description to include some of the following points

• selective weedkillers
• allows broad-leaved plants to grow uncontrollably and die
• narrower-leaved plants and crops left unaffected
• auxins and or gibberellins are used

• rooting powders
• plant cuttings are dipped into rooting powder
• roots develop rapidly
• large number of plants can be produced from the same
plant
• no need to wait for plants to grow from seeds
• auxins are used

• seedless fruit production

• the fruit will develop but the seeds inside will not
• fruits are able to grow larger (larger biomass) (6)
• gibberellins are used

Level 0 No rewardable content

1 1-2 • a limited description of at least one use of plant hormones

• the answer communicates ideas using simple language and uses
limited scientific terminology
• spelling, punctuation and grammar are used with limited accuracy
2 3-4 • a simple description of two or more uses of plant hormones
• the answer communicates ideas showing some evidence of clarity
and organisation and uses scientific terminology appropriately
• spelling, punctuation and grammar are used with some accuracy
3 5-6 • a detailed description of two or more uses of plant hormones with
at least auxin, gibberellins or other relevant hormone in the correct
context
• the answer communicates ideas clearly and coherently uses a range
of scientific terminology accurately
• spelling, punctuation and grammar are used with few errors

Total for question 5 = 12 marks

Question Answer Acceptable answers Mark
Number

6(a)(i) 75% (1)

Question Answer Acceptable answers Mark

Number
An explanation linking two of the accept ratios or probabilities
6(a)(ii) following: instead of percentages

• Punnett square would

predict 50% normal 50%
carrier (1)
actual offspring are 75%
• actual offspring are not
50% carrier (1)
accept references to random
• the probability is applied to assortment
each child not the overall (2)
offspring (1)

Question Answer Acceptable answers Mark

Number
Accept reverse order for gametes
6(a)(iii) b b Accept letters other than B/b
(but alleles must be the same
B Bb Bb letter)

b bb bb

Probability = 50%
Ratio 2/4, 2:2, can be given for 50% mark can only be given if
probability 50% of the offspring are
homozygous recessive

1 mark for correct gametes

(2)
1 mark for completed Punnett
square with correct probability

Question Answer Acceptable answers Mark

Number

6(a)(iv) A 6 homozygous dominant (1)

(BB)
Question Indicative Content Mark
Number
QWC *6(b) A explanation to include some of the following points:

Pedigree analysis would show the likelihood of their offspring

inheriting the disorder
Pedigree analysis should also be carried out on the partners of the
third generation.
• X is not a carrier
• X is homozygous dominant
• and does not have sickle cell disease
• The parents of X are heterozygous / his sister has sickle cell
• so will not pass on the allele for the disease to offspring
• if his partner is a carrier
• there will be a 50% chance of the child being a carrier

• Y and Z are carriers of the sickle cell allele

• Y and Z are heterozygous
• The mother of Y has sickle cell / Y will inherit the sickle cell
allele
• The parents of Z do not have sickle cell / mother is a
carrier/heterozygous
• They have a 50% chance of passing the sickle cell allele
onto their potential offspring
• If their partners were also carriers
• There would be a 25% chance that the offspring will have
the sickle cell disease
• There would be a 50% chance that the offspring would also
carry the allele for sickle cell disease
Example Punnett square:

B b
B BB Bb (6)
b Bb bb
Level 0 No rewardable content
1 1-2 • a limited explanation the genetic profile of X,Y and Z or an
explanation of the use of pedigree analysis
• the answer communicates ideas using simple language and uses
limited scientific terminology
• spelling, punctuation and grammar are used with limited accuracy
2 3-4 • A simple explanation of the genetic profile of X, Y and Z and an
explanation of the use of pedigree analysis
• the answer communicates ideas showing some evidence of clarity
and organisation and uses scientific terminology appropriately
• spelling, punctuation and grammar are used with some accuracy
3 5-6 • a detailed explanation of the genetic profile of X, Y and Z and
explanation of the use of pedigree analysis plus either an
explanation of one genotype or a prediction of one of the offspring
outcomes
• the answer communicates ideas clearly and coherently uses a range
of scientific terminology accurately
• spelling, punctuation and grammar are used with few errors
Total for Question 6 – 12 marks
Further copies of this publication are available from
Edexcel Publications, Adamsway, Mansfield, Notts, NG18 4FN

Telephone 01623 467467

Fax 01623 450481
Email publication.orders@edexcel.com
Order Code UG035089
March 2013

For more information on Edexcel qualifications, please visit our website

www.edexcel.com

Pearson Education Limited. Registered company number 872828

with its registered office at Edinburgh Gate, Harlow, Essex CM20 2JE