OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
1
Zinc ions are necessary for the enzyme carbonic anhydrase to work.
Which statement correctly describes the nature and function of zinc ions in their
interaction with carbonic anhydrase?
A
inorganic ions and coenzymes
B
vitamins and prosthetic groups
C
inorganic ions and prosthetic groups
D
vitamins and coenzymes
Your answer
2
[1]
Three types of microscope are listed below.
Select the row that shows the correct use for each type of microscope.
Type of microscope and what it is used to observe
Light
microscope
Transmission
electron
microscope
A
an object at a
certain depth
within a cell
cell surfaces
organelles
B
an object at a
certain depth
within a cell
cell surfaces
whole cells and
tissues
whole cells and
tissues
organelles
C
whole cells and
tissues
organelles
D
Your answer
© OCR 2016
Laser scanning
confocal
microscope
cell surfaces
an object at a
certain depth
within a cell
[1]
Page 1
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
3
A length of DNA has the base sequence AATCGCGGTCGCTCA.
Select the row that shows the correct complementary DNA strand and the sequence of
mRNA made during transcription of the DNA sequence above.
A
B
C
D
Complementary DNA sequence
AATCGCGGTCGCTCA
TTAGCGCCAGCGAGT
TTAGCGCCAGCGAGT
TTAGCGCCAGCGAGT
mRNA sequence
UUAGCGCCAGCGAGU
UUAGCGCCAGCGAGU
TTAGCGCCAGCGAGT
AAUCGCGGUCGCUCA
Your answer
4
[1]
There are two types of nuclear division, mitosis and meiosis. Meiosis incorporates two
divisions of the nucleus.
Which table shows the correct results of nuclear division?
A
C
Genetic
Reduction
Variation division
Genetic
Variation
Reduction
division
Mitosis
X
X
Mitosis
X
✓
Meiosis 1
✓
✓
Meiosis 1
✓
X
Meiosis 2
X
X
Meiosis 2
✓
✓
B
D
Genetic
Reduction
Variation division
Genetic
Variation
Reduction
division
Mitosis
X
X
Mitosis
X
X
Meiosis 1
✓
✓
Meiosis 1
✓
✓
Meiosis 2
✓
X
Meiosis 2
X
✓
Your answer
© OCR 2016
[1]
Page 2
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
5
Which of the following formulae of fatty acids represents a saturated fatty acid?
Statement 1:
Palmitic acid, C15H31COOH
Statement 2:
Oleic acid, C17H33COOH
Statement 3:
Linoleic acid, C17H31COOH
A
1, 2 and 3
B
Only 1 and 2
C
Only 2 and 3
D
Only 1
Your answer
© OCR 2016
[1]
Page 3
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
6
(a)
Glucose can be moved into cells by facilitated diffusion using proteins called GLUT
proteins. These proteins expose a single binding site on one side of the membrane.
Glucose binds to this site and causes a change in the shape of the protein. This
change moves the glucose across the membrane and releases it on the other side.
(i)
Explain why facilitated diffusion via GLUT proteins requires no metabolic
energy.
………………………………………………………………………………………
………………………………………………………………………………………
………………………………………………………………………………………
……………………………………………………………………………………
(ii)
Glucose can also be absorbed by an active process which requires metabolic
energy. What is the immediate source of this energy in cells?
…………………………………………………………………………………
(iii)
[2]
[1]
Explain why glucose cannot pass through a cell membrane by simple
diffusion.
……………………………………………………………………………………..
……………………………………………………………………………………..
……………………………………………………………………………………..
…………………………………………………………………………………… [2]
(b)
A student investigated the effect of alcohol on the permeability of membranes in
plant cells. The student wanted to find the minimum concentration of alcohol at
which all the cells became permeable to the stain Evans Blue. Evans Blue stains
the nucleus of the cell.
The student followed this method:




© OCR 2016
The student placed samples of onion epidermis into different concentrations of
ethanol.
After five minutes a few drops of Evans Blue stain was added to each sample.
After a further five minutes, the samples were viewed using a light
microscope.
The student observed 20 cells and recorded how many contained a blue
nucleus.
Page 4
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
Table 21.1 shows the student’s results.
Concentration of
ethanol (%)
0
10
20
30
40
Number of cells
with a blue nucleus
1
4
16
20
20
% cells with blue
nucleus
5
20
80
100
100
Table 21.1
(i)
Identify one limitation of the method the student followed.
…………………………………………………………………………………………
……………………………………………………………………………………
(ii)
[1]
On evaluating the results the student decided to use a narrower range of
ethanol concentrations.
Suggest what range of ethanol concentrations the student should use and
give a reason for your choice.
..…………………………………………………………………………………………
..…………………………………………………………………………………………
..…………………………………………………………………………………………
…………………………………………………………………………..………
(iii)
[2]
How would using a narrower range of alcohol concentrations improve the
investigation?
……..……………………………………………………………………………………
…...………………………………………………………………………………… [1]
© OCR 2016
Page 5
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
7
(a)
Fig. 22.1 shows a transverse section of the stem of a typical pondweed viewed
using a ×10 objective lens. Part of a graticule is shown below the stem. The
markings on the graticule are 0.1 mm apart.
vascular
bundle
A
B
air space
(i)
Measure the width of the stem between points A and B.
Give your answer to the nearest 0.1 mm.
Answer…………………………………… [1]
(ii)
Calculate the magnification of the image in Fig. 22.1.
Answer…………………………………..
[2]
(iii) The thin stem and thin cell walls do not provide much support for the leaf.
Suggest how the leaf is supported.
………………………………………………………………………………………
………………………………………………………………………………………
……………………………………………………………………………………
© OCR 2016
[2]
Page 6
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
(b)
A student was asked to view cells from the phloem in transverse section using a
high power objective lens. Fig. 22.2 shows two diagrams of phloem tissue.
(i)
Which diagram is the more accurate representation of what the student could
see?
Justify your decision using two separate features of the diagrams.
………………………………..…………….…………………………………………..
…………………………………..…………….………………………………………..
…………………………………..……………….……………………………………..
………………………………..………………………………………………..
(ii)
[2]
State what is meant by the resolution of a microscope.
…………..………………………………………………………………………………
…………………………………………………………………………………
© OCR 2016
[1]
Page 7
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
(iii)
The slide viewed to draw the diagrams in Fig. 22.2 had been stained.
Table 22.1 shows a list of stains and the cell feature that can be stained.
Stain
Nile blue
eosin
Sudan red
iodine
Cell feature
stained
nuclei
cytoplasm
cell membrane
starch
Which stain had the student used? Explain your answer.
……………………………..……....……………………………………………………
…………………………..………....……………………………………………………
……………………………..……....……………………………………………………
……………………………………..………………………………………….
8
[2]
Amylase activity is increased in the presence of chloride ions.
State the name given to any inorganic ion that increases the activity of an enzyme.
……………………………………………………………………………………….…………
© OCR 2016
Page 8
[1]
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
9
(i)
Outline how the process of DNA replication is completed, following the pairing
of nitrogenous bases.
………………………………………………………………………………………
………………………………………………………………………………………
………………………………………………………………………………………
………………………………………………………………………………………
………………………………………………………………………………………
………………………………………………………………………………………
……………………………………………………………………………………. [3]
(ii)
Why is DNA replication described as semi-conservative?
…………………………………………….…………………………………………..
…………………………………………………………………………………
© OCR 2016
[1]
Page 9
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
10
A group of microorganisms called slime moulds includes the species Dictyostelium
discoideum.
1
When plenty of food is available this slime mould exists as single-celled individuals
which feed and reproduce asexually.
The slime mould cells feed on bacteria.
The slime mould cells are attracted to folic acid which has been released by the
bacteria.
2
When food becomes scarce the slime mould cells release a chemical (cAMP) which
attracts other slime mould cells.
3
The slime mould cells then group and stick together to form a multicellular mass
called a grex.
The grex moves in a coordinated way in search of a more suitable environment.
As the grex moves, the cells release the chemical DIF. DIF causes some cells to
become stalk cells and others to become spore cells.
4
When the grex reaches suitable conditions, it forms a fruiting body consisting of a
stalk and spores.
These spores are released and develop into new, individual, slime mould cells.
© OCR 2016
Page 10
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
(a)
(i)
Suggest the type of cell division used by D. discoideum for reproduction during
stage 1 of its life cycle.
..................................................................................................................... [1]
(ii)
At what stage of the life cycle does differentiation begin?
...................................................................................................................
(b)
[1]
Communication and cooperation between cells is essential for the survival of
D. discoideum.
(i)
State the correct term for communication between cells.
..................................................................................................................
(ii)
[1]
Describe two examples of communication between cells that occur during the
life cycle of D. discoideum.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
..................................................................................................................... [2]
(iii)
The plasma membranes of the slime mould cells are specially adapted for
communication.
Suggest how the plasma membrane of D. discoideum is adapted for cell
communication.
…………………………………………………………………………………………
..……………………………………………………………………………………….
……………………………………………………………………………….……….
……………………………………………………………………………….
© OCR 2016
[2]
Page 11
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
11
(c)
In the past, beef was preserved by adding salt.
Explain how salting preserves food.
................................................................................................................................
................................................................................................................................
................................................................................................................................
................................................................................................................................
................................................................................................................................
...............................................................................................................................
...............................................................................................................................
...............................................................................................................................
.......................................................................................................................
© OCR 2016
[3]
Page 12
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
12
(a)
(i)
Name the cell components labelled A and B.
A .........................................................................................................................
B ..........................................................................................................
(ii)
[2]
State the functions of the components labelled C and D.
C ........................................................................................................................
............................................................................................................................
............................................................................................................................
D .........................................................................................................................
............................................................................................................................
...............................................................................................................
© OCR 2016
[2]
Page 13
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
(b)
A student suggested that the details of component C could be seen clearly with a
very good light microscope.
Explain why the student is not correct.
......................................................................................................................................
......................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.............................................................................................................................
13
(a)
[2]
Alcohol dehydrogenase is a protein molecule that is present in the liver. The
molecule breaks down alcohols and other chemicals that would otherwise be toxic
to the body.
Name the group of biological molecules to which alcohol dehydrogenase belongs.
..........................................................................................................................
© OCR 2016
[1]
Page 14
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
(b)
In 1985, health concerns were raised when the compound diethylene glycol (DEG)
was detected in samples of wine. The DEG had been added, illegally, to make the
wine taste sweeter.
In the liver, DEG is broken down by alcohol dehydrogenase to form a toxic product.
Alcohol dehydrogenase also breaks down ethanol, the key ingredient in alcoholic
drinks such as wine, to form a non-toxic product.
Fig. 2.1 shows the structures of DEG and ethanol.
(i)
Using the information in Fig. 2.1, explain why alcohol dehydrogenase is able
to breakdown both ethanol and DEG.
............................................................................................................................
............................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
....................................................................................................................... [3]
© OCR 2016
Page 15
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
(ii)
Suggest why DEG-contaminated wines with a high ethanol content may result
in less DEG poisoning than contaminated wines with a low ethanol content.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
....................................................................................................................... [3]
© OCR 2016
Page 16
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
14
Genes are important in the process of natural selection. Genes are made of DNA.
(i)
State the role of a gene.
............................................................................................................................
................................................................................................................
(ii)
[1]
Explain how the structure of DNA allows replication.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
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............................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
.................................................................................................................
© OCR 2016
[5]
Page 17
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
15
(a)
Amino acids form part of the structure of proteins.
(i)
State the name given to the sequence of amino acids in a protein molecule.
.................................................................................................................
(ii)
[1]
Draw the general structure of an amino acid molecule in the space below.
[3]
(b)
Collagen is an important fibrous protein which forms part of the wall of blood
vessels.
State one property of collagen that makes it a useful component of blood vessel
walls.
……………………………………………………………………………………...
(c)
[1]
Another protein that is important in mammals is haemoglobin.
State one function of haemoglobin.
...............................................................................................................................
.......................................................................................................................
[1]
[Total Marks: 64]
© OCR 2016
Page 18
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
MARK SCHEME
Question
1
Mks
1
Answer
C
Question Source and Guidance Notes
2
1
D
Q6-GCE-Biology A-Specimen-H020/01
3
1
B
Q9-GCE-Biology A-Specimen-H020/01
4
1
B
Q11-GCE-Biology A-Specimen-H020/01
5
1
D
Q18-GCE-Biology A-Specimen-H020/01
6 (a)(i)
2
particles have (their own) kinetic energy ✓
Q21(a)(i)-GCE-Biology -Specimen-H020/01
(movement) down concentration gradient ✓
ALLOW glucose for particles.
Q4-GCE-Biology A-Specimen-H020/01
ALLOW from high(er) concentration to low(er)
concentration
6 (a)(ii)
1
6 (a)(iii)
2
ATP ./
Q21(a)(ii)-GCE-Biology A-Specimen-H020/01
Topics
Foundations in Biology;
Enzymes
Foundations in Biology;
Cell Structure
Foundations in Biology;
Nucleotides and nucleic acids
Foundations in Biology;
Cell division, cell diversity and
cellular organisation
Foundations in Biology;
Biological molecules
Demand
M
Foundations in Biology;
Biological molecules
L,M,H
M
M
M
H
ALLOW adenosine triphosphate
6(b)(i)
1
phospholipids act as a barrier ✓
(glucose) molecules too large ✓
Q21(a)(iii)-GCE-Biology -Specimen-H020/01
one from
Q21(b)(i)-GCE-Biology A-Specimen-H020/01
Practical Skills; Planning;
Analysis; Evaluation
L,M
Q21(b)(ii)-GCE-Biology A-Specimen-H020/01
Practical Skills; Planning;
Analysis; Evaluation
L,M
Practical Skills; Planning;
Analysis; Evaluation
L,M
ALLOW (glucose) not soluble in phospholipid bilayer
because of polar –OH groups for 2 marks
volume of ethanol not given ✓
6(b)(ii)
6(b)(iii)
2
1
© OCR 2016
same onion / size of onion epidermis / position of
epidermis in onion not stated ✓
20–30% ✓
lowest concentration must be between 20 and
30% ✓
idea of more accurate determination of
permeability ✓
idea that 100% blue nuclei is not reached at 20% but is
reached at 30%
Q21(b)(iii)-GCE-Biology A-Specimen-H020/01
Page 14
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
Question
7(a)(i)
7(a)(ii)
Mks
1
2
Answer
Question Source and Guidance Notes
1.7 mm ✓
× 50 ✓
Q22(a)(i)-GCE-Biology A-Specimen-H020/01
Topics
Demand
Practical Skills; Implementing
L,M
Practical Skills; Implementing
L,M
Foundations in Biology;
Biological molecules
L
Q22(a)(ii)-GCE-Biology A-Specimen-H020/01
ALLOW 1 mark for correct working e.g. 80/1.6
ALLOW answer in the range of 48–51
7(a)(iii)
1
air spaces give buoyancy ✓
Q22(a)(iii)-GCE-Biology A-Specimen-H020/01
7(b)(i)
2
supported by (surrounding) water ✓
B
Q22(b)(i)-GCE-Biology A- Specimen-H020/01
No Mark for identification of B
comment about detail of organelles ✓
comment about shapes of cells ✓
e.g. light microscope would not allow nuclear pores /
ribosomes / endoplasmic reticulum / plasmodesmata to be
seen.
e.g. sieve tube elements are angular / hexagonal.
7(b)(ii)
1
7(b)(iii)
2
the ability to, see more detail / separate two
objects ✓
Nile blue ✓
1
to increase contrast / to make nuclei visible / to
show no nuclei in sieve tubes ✓
cofactor ./
8
Q22(b)(ii)-GCE-Biology A-Specimen-H020/01
Q22(b)(iii)-GCE-Biology A-Specimen-H020/01
Q2(d)-GCE-Biology A-Specimen-H020/02
IGNORE coenzyme.
9(i)
3
(involves) DNA polymerase ./
Q6(b)(i)-GCE-Biology A-Specimen-H020/02
ALLOW higher level answers
sugar-phosphate backbone
(re)forms/condensation reaction between
phosphate and sugar ./
9(ii)
1
10(a)(i)
1
DNA winds into double helix ./
(new molecule consists of) one old strand and
one new strand ./
mitosis ;
e.g. role of DNA ligase in joining sugar-phosphate
backbone lagging strand filled in with Okazaki fragments.
© OCR 2016
in the grex / 3 ;
Foundations in Biology;
Cell division, cell diversity and
cellular organisation
L,M
Q5(a)(i)-GCE-Biology -June 2014-F211/01
ACCEPT binary fission
1
M,H
Q6(b)(ii)-GCE-Biology A-Specimen-H020/02
CREDIT correct spelling only
10(a)(ii)
Foundations in Biology;
Nucleotides and nucleic acids
Q5(a)(ii)-GCE-Biology -June 2014-F211/01
Page 15
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
Question
10(b)(i)
10(b)(ii)
Mks
1
2
Answer
cell signalling ;
Question Source and Guidance Notes
1 attraction of cell(s) to folic acid from bacteria ;
NOTE must name the chemical involved for description
(except mp 3 coordinated movement)
Topics
Demand
Foundations in Biology;
Biological molecules
L,H
Q5(b)(i)-GCE-Biology -June 2014-F211/01
Q5(b)(ii)-GCE-Biology -June 2014-F211/01
2 attraction of cells to each other by cAMP ;
ACCEPT attraction of cells to bacteria by folic acid
3 coordinated movement in grex ;
IGNORE makes cells stick together
4 differentiation / described, of (grex / slime
mould) cells in response to DIF ;
10(b)(iii)
2
contains , receptors / glycoproteins / glycolipids /
Q5(b)(iii)-GCE-Biology -June 2014-F211/01
DO NOT CREDIT consists of receptors
glycocalyx ;
11
3
for , folic acid / cAMP / DIF;
1 reduces , water potential / Ψ , outside ,
microbial / bacterial / fungal , cells ;
Q7(c)-GCE-Biology -June 2014-F212/01
1 Cannot be implied from references to water potential
gradient
Foundations in Biology;
Biological molecules
L,M,H
1 ACCEPT reduces beef water potential
2 (microbes) lose water and cannot , reproduce /
survive / carry out metabolic reactions / AW ;
1 IGNORE solute potential
1 IGNORE viruses
3 water moves by osmosis ;
2 ACCEPT bacteria lose water and die
2 AWARD only in context of microbes dehydrating
2 IGNORE viruses
2 IGNORE beef losing water so microbes cant reproduce
3 ACCEPT in any correct water potential contex
© OCR 2016
Page 16
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
Question
12(a)(i)
Mks
2
Answer
Question Source and Guidance Notes
Q1(a)(i)-GCE-Biology - June 2013-F211/01
Mark the first answer on each prompt line. If the answer
A nucleus ;
is correct and an additional answer is given that is
incorrect or contradicts the correct answer then = 0 marks
B chloroplast ;
DO NOT CREDIT nuclear envelope / nucleolus
Topics
Foundations in Biology;
Cell Structure
Demand
L,M
Foundations in Biology;
Cell Structure
L,M
Foundations in Biology;
Cell Structure
M,H
IGNORE chlorophyll
12(a)(ii)
Q1(a)(ii)-GCE-Biology - June 2013-F211/01
2
C mitochondrion
(aerobic) respiration / producing ATP / release
energy ;
Mark the first answer on each prompt line. If the answer
is correct and an additional answer is given that is
incorrect or contradicts the correct answer then = 0 marks
DO NOT CREDIT Function of organelle if organelle
identified / named incorrectly (as this would be an incorrect
biological statement.
D SER / smooth endoplasmic reticulum
transport / production / processing, of, fats /
lipids /
steroids / carbohydrates
DO NOT CREDIT makes / produces, energy
ACCEPT produces ATP for respiration
IGNORE ref to transport / modification of proteins
DO NOT CREDIT ref production of proteins
12(b)
2
C / mitochondrion / cristae, too small ;
Q1(b)-GCE-Biology - June 2013-F211/01
idea of too small / not big enough important
resolution (of light microscope), not high
(enough)
IGNORE very small
OR idea of only, 0.2μm / 200nm ;
ACCEPT resolution low
wavelength of light too long ;
IGNORE ref to magnification
for resolution accept any value in range 0.05 - 0.2 μm
IGNORE ref to electron microscope
© OCR 2016
Page 17
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
Question
13(a)
Mks
1
Answer
enzymes ;
Question Source and Guidance Notes
Q2(a)-GCE-Biology -June 2013-F212/01
IGNORE protein / catalysts
Topics
Foundations in Biology;
Enzymes
Demand
L
ACCEPT enzymic
13(b)(i)
3
1 similar, shape / structure ;
Q2(b)(i)-GCE-Biology -June 2013-F212/01
1 IGNORE same shape
1 ACCEPT ‘ethanol same shape as part of DEG’
2 example of similarity ;
2 IGNORE they contain C, H and O
2 IGNORE the end is the same
2 ACCEPT e.g. they both have OH
3 both, will fit into / complementary (shape) to /
bind to / bond to , active site (of alcohol
dehydrogenase ) ;
2 ACCEPT similar parts identified on diagram if they are
clearly indicating an example of similarity
3 ACCEPT implication of both
3 IGNORE attach / enter
3 IGNORE both will form ESC (with alcohol
dehydrogenase)
13(b)(ii)
3
1 (ethanol) competes with DEG ; ora
Foundations in Biology;
Enzymes
L,M,H
Q2(b)(ii)-GCE-Biology -June 2013-F212/01
1 ACCEPT ethanol / DEG , is , a competitive inhibitor
2 (when at high(er) concentration) ethanol more
likely to , collide with / bind to / bond to , active
site ; ora
3 less , DEG breakdown / toxic product ; ora
2 ACCEPT ‘ethanol more likely to form ESC’
2 ACCEPT implication of ‘more likely’ from context
2 IGNORE attach / enter
3 ACCEPT DEG product is diluted
3 ACCEPT no DEG breakdown
IGNORE ‘you will drink less of it’
© OCR 2016
Page 18
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
Question
14(i)
Mks
1
Answer
Question Source and Guidance Notes
code for (one or more) polypeptide(s) ;
Q5(d)(i)-GCE-Biology - June 2014-F212/01
Topics
Demand
Foundations in Biology;
Nucleotides and nucleic acids
L,M,H
ACCEPT protein
IGNORE amino acid sequence
14(ii)
5
1 double stranded ;
Q5(d)(ii)-GCE-Biology -June 2014-F212/01
AWARD marks from clearly annotated diagram
2 each / both (strands) act as template ;
3 hydrogen bonds , easily , break / form ,
between
1 ACCEPT double helix or two , polynucleotides / strands /
chains or antiparallel strands
1 IGNORE one old and one new strand
bases ;
2 IGNORE either
4 complementary (specified) base , pairing / AW
;
NOTE ‘there are 2 strands which act as templates’ = 2
marks (mp 1 and 2)
5 purine (only able to) bind to pyrimidine ;
3 ACCEPT weak H bonds between bases break
6 (due to) different sizes of purines and
pyrimidines ;
7 hydrogen bonding different between A & T and
C&G
or
3 H bonds between C & G and
2 H bonds between A & T ;
3 IGNORE refs to H bonds , breaking / forming , without
qualification that the bonds are weak or , form / break ,
easily
4 IGNORE complementary nucleotides unless qualified
with examples of base-pairing
7 ACCEPT names of bases with phonetic spellings
7 DO NOT CREDIT thyamine
7ACCEPT A=T and C≡G without reference to hydrogen
bonds
© OCR 2016
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OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
Question
15(a)(i)
Mks
1
Answer
primary structure ;
Question Source and Guidance Notes
Topics
Demand
Foundations in Biology;
Biological molecules
L,M
Q1(a)(i)-GCE-Biology -June 2013-F212/01
ACCEPT 1o structure
IGNORE polypeptide
15(a)(ii)
3
NH2 at one end ;
COOH at opposite end ;
Q1(a)(ii)-GCE-Biology -June 2013-F212/01
If R group not shown as ‘R’ then award max 2 (as general
structure asked for in Q)
C in centre (of a single amino acid) bonded
IGNORE labels
(separately) to one R and one H ;
ACCEPT displayed structure of NH2 / HNH
ACCEPT displayed structure of COOH if correct double
bond shown
AWARD only if the candidate has drawn a single ‘amino
acid’ Molecule
H
H2N
C
COOH
R
© OCR 2016
Page 20
OCR AS/A Level Biology A (H020/H420)
Module 2 Topic Test – Foundations in Biology
Question
15(b)
Mks
1
Answer
strength / toughness / insolubility ;
Question Source and Guidance Notes
Q1(b)(i)-GCE-Biology -June 2013-F212/01
Mark the first answer. If the answer is correct and an
additional answer is given that is incorrect or contradicts
the correct answer then = 0 marks
Topics
Foundations in Biology;
Biological molecules
Demand
L,M,H
Foundations in Biology;
Biological molecules
L,M,H
ACCEPT strong / tough
IGNORE flexible / inelastic
IGNORE withstand pressure
15(c)
1
transport / AW , of, oxygen / O2 ;
Q1(c)(i)-GCE-Biology -June 2013-F212/01
Mark the first answer. If the answer is correct and an
additional answer is given that is incorrect or contradicts
the correct answer then = 0 marks
ACCEPT buffering blood / carrying CO2 / storing oxygen
IGNORE binding oxygen
IGNORE Iron
Total
64
OCR Resources: the small print
OCR’s resources are provided to support the teaching of OCR specifications, but in no way constitute an endorsed teaching method that is required by the Board, and the
decision to use them lies with the individual teacher. Whilst every effort is made to ensure the accuracy of the content, OCR cannot be held responsible for any errors or
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© OCR 2016
© OCR 2016
Page 21