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171737 unit h420 01 biological processes sample assessment materials
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© OCR 2016
[601/4260/1] DC (...) H420/01 Turn over
Oxford Cambridge and RSA
A Level Biology A
H420/01 Biological processes
Sample Question Paper
Date – Morning/Afternoon Version 2.
Time allowed: 2 hours 15 minutes
You may use
• a scientific or graphical calculator
####### * 0 0 0 0 0 0 *
First name
Last name
Centre
number
Candidate
number
INSTRUCTIONS
• Use black ink. You may use an HB pencil for graphs and diagrams.
• Complete the boxes above with your name, centre number and candidate number.
• Answer all the questions.
• Where appropriate, your answers should be supported with working. Marks may
be given for a correct method even if the answer is incorrect.
• Write your answer to each question in the space provided.
• Additional paper may be used if required but you must clearly show your candidate
number, centre number and question number(s).
• Do not write in the bar codes.
INFORMATION
• The total mark for this paper is 100.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document consists of 28 pages.
© OCR 2016 H420/
SECTION A
You should spend a maximum of 20 minutes on this section.
Answer all the questions.
1 Which statement explains the significance of mitosis in the development of whole organisms?
A Mitosis can be controlled at certain points in development, which will change body plans.
B Sex cells are produced by mitosis, which allows new organisms to be produced.
C Mitosis limits the total number of cells in an organism, which will change its shape.
D Budding in yeast is an example of mitosis, producing new multicellular organisms.
Your answer [1]
2 Which graph represents the counter-current exchange system in fish gills?
Your answer [1]
© OCR 2016 H420/
6 The following mechanisms are used to move water through plants:
i) diffusion
ii) osmosis
iii) mass flow.
Which row correctly identifies the mechanism used at each point of the transpiration stream?
Into root
cells
Across root
via symplast
pathway
Up the stem in
the xylem
Across leaf via
apoplast
pathway
Out of leaf via
stomata
A osmosis osmosis mass flow mass flow diffusion
B diffusion osmosis osmosis mass flow diffusion
C diffusion osmosis osmosis mass flow osmosis
D osmosis osmosis mass flow mass flow osmosis
Your answer [1]
7 Citrate synthase catalyses the conversion of oxaloacetate into citric acid in the Krebs cycle. It exhibits
product inhibition.
Which of the following is the correct description of citrate synthase?
Type of respiration
involved in
Location of enzyme Inhibitor
A anaerobic cytoplasm citric acid
B aerobic mitochondria citric acid
C aerobic mitochondria oxaloacetate
D anaerobic cytoplasm oxaloacetate
Your answer [1]
© OCR 2016 H420/01 Turn over
8 Which of the following describes the process that happens during repolarisation of a neurone during
the action potential?
Sodium channels Potassium
channels
Membrane
potential
A closed open decreasing
B open closed decreasing
C open closed increasing
D closed open increasing
Your answer [1]
9 An unknown solution of a single sugar was tested. The results were recorded in Table 9.
Colours observed after testing
Benedict’s test for reducing sugars Benedict’s test for non-reducing sugars
blue brick red
Table 9.
Identify the unknown sugar.
A fructose
B lactose
C sucrose
D glucose
Your answer [1]
10 An anticodon sequence of five successive tRNA molecules involved in protein synthesis was analysed
and found to have the following percentage base composition.
Adenine 40; Cytosine 27; Guanine 13; Thymine 0; Uracil 20 %
Which row shows the percentage base composition of the template strand of the original DNA
molecule?
Adenine Cytosine Guanine Thymine Uracil
A 40 27 13 20 0
B 20 13 27 40 0
C 20 13 27 0 40
D 40 27 13 0 20
Your answer [1]
© OCR 2016 H420/01 Turn over
12 Which of the following is/are interventions in the control of blood glucose concentration?
Statement 1: Insulin injection.
Statement 2: Regular cardiovascular exercise.
Statement 3: Glucagon injection.
A 1, 2 and 3
B Only 1 and 2
C Only 2 and 3
D Only 1
Your answer [1]
13 Which of the following statements is/are true?
Statement 1: Microtubules are part of the ‘9 + 2’ formation in bacterial flagella.
Statement 2: Microtubules can be prevented from functioning by a respiratory inhibitor.
Statement 3: Microtubules are involved in moving chromosomes from the equator to the poles of
the cell during mitosis.
A 1, 2 and 3
B Only 1 and 2
C Only 2 and 3
D Only 1
Your answer [1]
© OCR 2016 H420/
14 Blood vessels are adapted for their function.
Which of the following statements is/are true?
Statement 1: The walls of arteries near the heart contain a lot of elastic fibres so that they can
stretch and recoil to maintain blood pressure.
Statement 2: The walls of the venules contain little muscle.
Statement 3: The walls of arteries contain a lot of muscle fibres to contract and generate pressure
in the blood.
A 1, 2 and 3
B Only 1 and 2
C Only 2 and 3
D Only 1
Your answer [1]
15 Phospholipid bilayers play crucial roles within plant cells.
Which of the following statements linked to the importance of membranes in plant cells is/are true?
Statement 1: ATP synthase embedded in thylakoid membranes maintains chemiosmotic
gradients.
Statement 2: Phospholipid bilayers within the chloroplast are impermeable to protons.
Statement 3: Thylakoid membranes contain electron transport chain proteins.
A 1, 2 and 3
B Only 1 and 2
C Only 2 and 3
D Only 1
Your answer [1]
© OCR 2016 H420/
(ii) The most obvious feature of tachycardia is an increased heart rate.
Using the information in Fig. 16, Fig. 16 and Fig. 16, what are other key features of
tachycardia?
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....................................................................................................... [2]
(b) Fig. 16 is an ECG trace of a person with an abnormal heart rhythm.
Fig. 16.
Using the information from Fig. 16, what conclusions can you draw about the way in which
this person’s heart is functioning abnormally?
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© OCR 2016 H420/01 Turn over
17 (a) Fig. 17 is a diagram of the external view of a mammalian liver.
Fig. 17.
Identify, with reasons, each of the blood vessels labelled A – C in Fig. 17.
A.............................................................................................................
...............................................................................................................
B.............................................................................................................
...............................................................................................................
C.............................................................................................................
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[3]
© OCR 2016 H420/01 Turn over
(c) Liver cells have a high metabolic rate. Hydrogen peroxide is a metabolic product produced in
significant quantities in liver cells. It needs to be removed in order to prevent serious damage to
the liver cells.
Hydrogen peroxide is detoxified by the enzyme catalase:
2 H 2 O 2 2 H 2 O + O 2
Catalase has a very high turnover number. A single catalase molecule can catalyse the breakdown
of approximately 6 million hydrogen peroxide molecules every minute. Catalase is found in
peroxisomes inside the liver cells. Peroxisomes are organelles surrounded by a single membrane.
The activity of catalase was investigated in a laboratory, using chopped liver tissue and dilute
hydrogen peroxide. When the chopped liver was added to the hydrogen peroxide large quantities
of froth as bubbles of oxygen were produced in the liquid.
Fig. 17 shows the effect of increasing enzyme concentration on the rate of the reaction.
Fig. 17.
(i) Identify two variables that would need to be controlled in this laboratory investigation.
1.............................................................................................................
2.............................................................................................................
[1]
(ii) How could you control one of the variables that you identified in (i) in the laboratory
investigation?
.............................................................................................................
....................................................................................................... [1]
© OCR 2016 H420/
(iii)* Using the information given in part (c), deduce why and how catalase activity is regulated
inside the liver cells. [6]
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Additional answer space if required.
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© OCR 2016 H420/
(b) Plants grow successfully in temperatures that are suited to their metabolism. Some plants are
adapted for growth in cool climates while others can grow well in warm climates.
Plants also vary in their photosynthetic metabolism. Many plants produce a 3-carbon compound
as the first product of carbon fixation and so are referred to as C3 plants. Another group of plants
produces a 4-carbon compound as the first product and so are referred to as C4 plants.
C3 plants include barley, lentil, rice, soya, sunflower and wheat.
C4 plants include maize, millet, sorghum and sugar cane.
Fig. 18 shows the assimilation of carbon dioxide by four different crops at different
temperatures.
Fig. 18.
(i) With reference to Fig. 18, what is the general relationship between increasing temperature
and the assimilation of carbon dioxide?
.............................................................................................................
.............................................................................................................
.............................................................................................................
....................................................................................................... [2]
© OCR 2016 H420/01 Turn over
(ii) Calculate the values for the mean assimilation of carbon dioxide by C3 plants and C4 plants
at 20 oC. Include units in your answer.
C
.............................................................................................................
C
.............................................................................................................
[2]
(iii) Suggest a conclusion that could be drawn from the mean values you calculated in part (ii).
.............................................................................................................
....................................................................................................... [1]
(iv) With reference to Fig. 18, suggest which curve corresponds to each of the following crops:
Sugar cane, which grows in warm climates.
.......................................................................................................
Barley, which grows in cool climates.
.......................................................................................................
[2]
© OCR 2016 H420/01 Turn over
19 (a) Following their formation, assimilates are transported throughout the plant by translocation in
phloem.
Phloem sap mainly consists of carbohydrate in the form of sucrose, but also contains other
solutes.
(i) Suggest why it is beneficial to the plant for the carbohydrate to be transferred throughout
the plant in the form of sucrose rather than as an alternative carbohydrate.
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(ii) How is transport in the phloem similar to and different from transport in the xylem?
Similar....................................................................................................
.............................................................................................................
Different..................................................................................................
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[2]
(b) Assimilates are loaded into the phloem at the ‘source’ and then transported to the ‘sink’.
(i) Explain, with a suitable example, how some parts of the plant can act as both a ‘source’ and
a ‘sink’.
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....................................................................................................... [2]
© OCR 2016 H420/
(ii)* Fig. 19 is a diagram that represents the loading of sucrose into the phloem at the ‘source’.
Fig. 19.
With reference to Fig. 19, explain the process of the loading of sucrose into the phloem
and its movement in the phloem. [6]
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companion cell
sieve
plate
phloem sieve
tube
Was this document helpful?
171737 unit h420 01 biological processes sample assessment materials
Subject: Computer Science
264 Documents
Students shared 264 documents in this course
Degree • Grade:
Sixth Form (A Levels)
• A2 - A LevelWas this document helpful?
© OCR 2016
[601/4260/1] DC (…) H420/01 Turn over
Oxford Cambridge and RSA
A Level Biology A
H420/01 Biological processes
Sample Question Paper
Date – Morning/Afternoon Version 2.2
Time allowed: 2 hours 15 minutes
You may use
• a scientific or graphical calculator
*
0
0
0
0
0
0
*
First name
Last name
Centre
number
Candidate
number
INSTRUCTIONS
• Use black ink. You may use an HB pencil for graphs and diagrams.
• Complete the boxes above with your name, centre number and candidate number.
• Answer all the questions.
• Where appropriate, your answers should be supported with working. Marks may
be given for a correct method even if the answer is incorrect.
• Write your answer to each question in the space provided.
• Additional paper may be used if required but you must clearly show your candidate
number, centre number and question number(s).
• Do not write in the bar codes.
INFORMATION
• The total mark for this paper is 100.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document consists of 28 pages.
Discover more from:
Computer Science
264 Documents
- Discover more from:Computer Science264 Documents
More from:Computer Science
More from:
Computer Science
264 Documents
- More from:Computer Science264 Documents
