PMT Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. H GCSE BIOLOGY Higher Tier Paper 2 H Friday 7 June 2024 Afternoon Time allowed: 1 hour 45 minutes Materials For Examiner’s Use For this paper you must have: • a ruler Question Mark • a scientific calculator. 1 Instructions 2 • Use black ink or black ball-point pen. 3 • Pencil should only be used for drawing. 4 • Fill in the boxes at the top of this page. 5 • Answer all questions in the spaces provided. • If you need extra space for your answer(s), use the lined pages at the end of 6 this book. Write the question number against your answer(s). 7 • Do all rough work in this book. Cross through any work you do not want 8 to be marked. • In all calculations, show clearly how you work out your answer. 9 TOTAL Information • The maximum mark for this paper is 100. • The marks for questions are shown in brackets. • You are expected to use a calculator where appropriate. • You are reminded of the need for good English and clear presentation in your answers. * JUN2484612H01 * 8461/2H IB/H/Jun24/E14

PMT
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
H
GCSE
BIOLOGY
Higher Tier Paper 2 H
Friday 7 June 2024 Afternoon Time allowed: 1 hour 45 minutes
Materials
For this paper you must have: For Examiner’s Use
• a ruler
Question Mark
• a scientific calculator.
1
Instructions 2
• Use black ink or black ball-point pen. 3
• Pencil should only be used for drawing.
4
• Fill in the boxes at the top of this page.
• Answer all questions in the spaces provided. 5
• If you need extra space for your answer(s), use the lined pages at the end of 6
this book. Write the question number against your answer(s). 7
• Do all rough work in this book. Cross through any work you do not want
8
to be marked.
• In all calculations, show clearly how you work out your answer. 9
TOTAL
Information
• The maximum mark for this paper is 100.
• The marks for questions are shown in brackets.
• You are expected to use a calculator where appropriate.
• You are reminded of the need for good English and clear presentation
in your answers.
* JUN2484612H01 * 8461/2H
IB/H/Jun24/E14

PMT 2 Do not write outside the Answer all questions in the spaces provided. box 0 1 Evolution of new species occurs by mutation and natural selection. 0 1 . 1 What is a mutation? [1 mark] 0 1 . 2 Describe the process of natural selection. [3 marks] 0 1 . 3 Which scientists suggested the theory of evolution by natural selection? [1 mark] Tick (  ) one box. Alexander Fleming and Carl Woese Alfred Wallace and Alexander Fleming Alfred Wallace and Charles Darwin Charles Darwin and Carl Woese 0 02 * IB/H/Jun24/8461/2H

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0 1 Evolution of new species occurs by mutation and natural selection.
0 1 . 1 What is a mutation?
[1 mark]
0 1 . 2 Describe the process of natural selection.
[3 marks]
0 1 . 3 Which scientists suggested the theory of evolution by natural selection?
[1 mark]
Tick (  ) one box.
Alexander Fleming and Carl Woese
Alfred Wallace and Alexander Fleming
Alfred Wallace and Charles Darwin
Charles Darwin and Carl Woese
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PMT 3 Do not write outside the 0 1 . 4 The hoverfly and the wasp are insects with bright yellow and black markings. box Figure 1 shows a hoverfly and a wasp. Figure 1 The wasp has a sting to defend itself against predators. The hoverfly does not have a sting. Hoverflies and wasps live in the same habitat. Explain how having yellow and black markings helps the hoverfly survive. [3 marks] 8 Turn over for the next question Turn over ► * 03 * IB/H/Jun24/8461/2H

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0 1 . 4 The hoverfly and the wasp are insects with bright yellow and black markings. box
Figure 1 shows a hoverfly and a wasp.
Figure 1
The wasp has a sting to defend itself against predators.
The hoverfly does not have a sting.
Hoverflies and wasps live in the same habitat.
Explain how having yellow and black markings helps the hoverfly survive.
[3 marks]
8
Turn over for the next question
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PMT 4 Do not write outside the 0 2 Peat bogs are estimated to contain twice as much carbon as all the world’s forests. box Figure 2 shows a section through part of a peat bog. Figure 2 Layer A contains a lot of air. Layer B : • contains the dead remains of plants • has a low pH • contains very little oxygen • contains carbon dioxide and methane. * 04 * IB/H/Jun24/8461/2H

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0 2 Peat bogs are estimated to contain twice as much carbon as all the world’s forests. box
Figure 2 shows a section through part of a peat bog.
Figure 2
Layer A contains a lot of air.
Layer B :
• contains the dead remains of plants
• has a low pH
• contains very little oxygen
• contains carbon dioxide and methane.
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PMT 5 Do not write outside the 0 2 . 1 Explain why most of the dead remains of plants in layer B do not decay. box [3 marks] 0 2 . 2 The peat bog in Figure 2 is a stable community. The moss produces biomass at a rate of 340 g/m 2 /year. What is the approximate biomass of the moss that becomes biomass in primary consumers? [1 mark] Tick (  ) one box. 2 0.34 g/m /year 2 3.4 g/m /year 2 34 g/m /year 2 340 g/m /year Question 2 continues on the next page Turn over ► * 05 * IB/H/Jun24/8461/2H

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0 2 . 1 Explain why most of the dead remains of plants in layer B do not decay. box
[3 marks]
0 2 . 2 The peat bog in Figure 2 is a stable community.
The moss produces biomass at a rate of 340 g/m 2 /year.
What is the approximate biomass of the moss that becomes biomass in primary
consumers?
[1 mark]
Tick (  ) one box.
0.34 g/m 2 /year
3.4 g/m 2 /year
34 g/m 2 /year
340 g/m 2 /year
Question 2 continues on the next page
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PMT 6 Do not write outside the The sundew plant shown in Figure 2 on page 4 has leaves with sticky hairs that box trap and digest insects. Digestion of the insects releases phosphates and simple compounds of nitrogen that are used by the sundew plant. 0 2 . 3 What substance can the sundew plant make using the phosphates ? [1 mark] Tick (  ) one box. Cellulose DNA Glycerol Starch 0 2 . 4 What substance can the sundew plant make using the nitrogen ? [1 mark] Tick (  ) one box. Fatty acid Glucose Lactic acid Protein * 06 * IB/H/Jun24/8461/2H

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The sundew plant shown in Figure 2 on page 4 has leaves with sticky hairs that box
trap and digest insects.
Digestion of the insects releases phosphates and simple compounds of nitrogen that
are used by the sundew plant.
0 2 . 3 What substance can the sundew plant make using the phosphates ?
[1 mark]
Tick (  ) one box.
Cellulose
DNA
Glycerol
Starch
0 2 . 4 What substance can the sundew plant make using the nitrogen ?
[1 mark]
Tick (  ) one box.
Fatty acid
Glucose
Lactic acid
Protein
* 06 *
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PMT 7 Do not write outside the 0 2 . 5 Humans have destroyed large areas of peat bog to collect peat. box The peat provides fuel and provides compost for gardeners to use. The peat comes from layer B in Figure 2 on page 4. Layer B : • contains the dead remains of plants • has a low pH • contains very little oxygen • contains carbon dioxide and methane. Figure 3 shows the removal of peat from a peat bog. Figure 3 Explain how the destruction of peat bogs and the use of peat affects the temperature of the Earth’s atmosphere. [4 marks] 10 Turn over ► * 07 * IB/H/Jun24/8461/2H

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0 2 . 5 Humans have destroyed large areas of peat bog to collect peat. box
The peat provides fuel and provides compost for gardeners to use.
The peat comes from layer B in Figure 2 on page 4.
Layer B :
• contains the dead remains of plants
• has a low pH
• contains very little oxygen
• contains carbon dioxide and methane.
Figure 3 shows the removal of peat from a peat bog.
Figure 3
Explain how the destruction of peat bogs and the use of peat affects the temperature
of the Earth’s atmosphere.
[4 marks]
10
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PMT 8 Do not write outside the Turn over for the next question box DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED * 08 * IB/H/Jun24/8461/2H

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DO NOT WRITE ON THIS PAGE
ANSWER IN THE SPACES PROVIDED
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PMT 9 Do not write outside the 0 3 Frogs are animals that lay their eggs in water. The eggs hatch as tadpoles. box Students investigated the number of tadpoles in a pond for 8 weeks. This is the method used. 1. Collect 10 dm 3 of pond water in a bucket. 2. Count the number of tadpoles collected. 3. Put the tadpoles back into the pond. 4. Repeat steps 1 to 3 another three times in different parts of the pond . 5. Repeat steps 1 to 4 at intervals for 8 weeks. 0 3 . 1 Suggest one improvement to the method. [1 mark] Question 3 continues on the next page Turn over ► * 09 * IB/H/Jun24/8461/2H

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0 3 Frogs are animals that lay their eggs in water. The eggs hatch as tadpoles. box
Students investigated the number of tadpoles in a pond for 8 weeks.
This is the method used.
1. Collect 10 dm 3 of pond water in a bucket.
2. Count the number of tadpoles collected.
3. Put the tadpoles back into the pond.
4. Repeat steps 1 to 3 another three times in different parts of the pond .
5. Repeat steps 1 to 4 at intervals for 8 weeks.
0 3 . 1 Suggest one improvement to the method.
[1 mark]
Question 3 continues on the next page
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PMT 10 Do not write outside the Table 1 shows the results. box Table 1 Number of tadpoles in each sample Sample number 0 weeks 1 week 2 weeks 3 weeks 5 weeks 8 weeks 1 11 17 8 9 5 0 2 15 11 12 7 0 5 3 23 16 14 10 7 3 4 11 14 16 X 4 4 Totals 60 58 50 32 16 12 0 3 . 2 Value X is the number of tadpoles in sample 4, at 3 weeks. Calculate value X . [1 mark] Value X = * 10 * IB/H/Jun24/8461/2H

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Table 1 shows the results. box
Table 1
Number of tadpoles in each sample
Sample
number
0 weeks 1 week 2 weeks 3 weeks 5 weeks 8 weeks
1 11 17 8 9 5 0
2 15 11 12 7 0 5
3 23 16 14 10 7 3
4 11 14 16 X 4 4
Totals 60 58 50 32 16 12
0 3 . 2 Value X is the number of tadpoles in sample 4, at 3 weeks.
Calculate value X .
[1 mark]
Value X =
* 10 *
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PMT 11 Do not write outside the 0 3 . 3 Complete Figure 4 to show how the total number of tadpoles changed over the box 8 weeks. [4 marks] You should: • label the x-axis • use a suitable scale for the x-axis • plot the data for the total numbers of tadpoles from Table 1 • draw a line of best fit. Figure 4 0 3 . 4 After 0 weeks, no more tadpoles hatched in the pond. Calculate the percentage of the tadpoles that would still be found in the pond at 4 weeks compared with 0 weeks. Use information from Figure 4 . [3 marks] Percentage of tadpoles found at 4 weeks = % Turn over ► * 11 * IB/H/Jun24/8461/2H

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0 3 . 3 Complete Figure 4 to show how the total number of tadpoles changed over the box
8 weeks.
[4 marks]
You should:
• label the x-axis
• use a suitable scale for the x-axis
• plot the data for the total numbers of tadpoles from Table 1
• draw a line of best fit.
Figure 4
0 3 . 4 After 0 weeks, no more tadpoles hatched in the pond.
Calculate the percentage of the tadpoles that would still be found in the pond at
4 weeks compared with 0 weeks.
Use information from Figure 4 .
[3 marks]
Percentage of tadpoles found at 4 weeks = %
Turn over ►
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PMT 12 Do not write outside the 0 3 . 5 After 4 weeks many of the tadpoles had died. box Suggest two reasons why the tadpoles died. [2 marks] 1 2 11 * 12 * IB/H/Jun24/8461/2H

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0 3 . 5 After 4 weeks many of the tadpoles had died. box
Suggest two reasons why the tadpoles died.
[2 marks]
1
2
11
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PMT 13 Do not write outside the Turn over for the next question box DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Turn over ► * 13 * IB/H/Jun24/8461/2H

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DO NOT WRITE ON THIS PAGE
ANSWER IN THE SPACES PROVIDED
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PMT 14 Do not write outside the 0 4 A student investigated the effect of gravity on the growth of bean seedlings. box The student put ink marks on the root of each bean seedling. Figure 5 shows a bean seedling with ink marks. Figure 5 The student set up apparatus A and apparatus B . Figure 6 shows both sets of apparatus. Figure 6 The student left both sets of apparatus in a dark cupboard for 24 hours. * 14 * IB/H/Jun24/8461/2H

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0 4 A student investigated the effect of gravity on the growth of bean seedlings. box
The student put ink marks on the root of each bean seedling.
Figure 5 shows a bean seedling with ink marks.
Figure 5
The student set up apparatus A and apparatus B .
Figure 6 shows both sets of apparatus.
Figure 6
The student left both sets of apparatus in a dark cupboard for 24 hours.
* 14 *
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PMT 15 Do not write outside the 0 4 . 1 Give the reason why the student placed both sets of apparatus in the dark. box [ 1 mark] 0 4 . 2 What are two reasons for surrounding the seedlings with damp blotting paper? [2 marks] Tick (  ) two box es . To prevent photosynthesis in the roots To prevent the growth of mould on the roots To prevent water affecting the direction of root growth To provide enough water for root growth To provide the roots with mineral ions 0 4 . 3 Apparatus B is a control. Explain why apparatus B is needed. [2 marks] Question 4 continues on the next page Turn over ► * 15 * IB/H/Jun24/8461/2H

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0 4 . 1 Give the reason why the student placed both sets of apparatus in the dark. box
[ 1 mark]
0 4 . 2 What are two reasons for surrounding the seedlings with damp blotting paper?
[2 marks]
Tick (  ) two box es .
To prevent photosynthesis in the roots
To prevent the growth of mould on the roots
To prevent water affecting the direction of root growth
To provide enough water for root growth
To provide the roots with mineral ions
0 4 . 3 Apparatus B is a control.
Explain why apparatus B is needed.
[2 marks]
Question 4 continues on the next page
Turn over ►
* 15 *
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PMT 16 Do not write outside the 0 4 . 4 Figure 7 shows one seedling from apparatus A at the start of the investigation and box after 24 hours. The drawing of the seedling after 24 hours is not complete. Figure 7 Complete Figure 7 to show: • the appearance of the root after 24 hours • the ink marks on the root after 24 hours. [3 marks] * 16 * IB/H/Jun24/8461/2H

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0 4 . 4 Figure 7 shows one seedling from apparatus A at the start of the investigation and box
after 24 hours.
The drawing of the seedling after 24 hours is not complete.
Figure 7
Complete Figure 7 to show:
• the appearance of the root after 24 hours
• the ink marks on the root after 24 hours.
[3 marks]
* 16 *
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PMT 17 Do not write outside the Figure 6 is repeated below. box Figure 6 The student left both sets of apparatus in a dark cupboard for 24 hours. 0 4 . 5 Describe how a root from apparatus B would look different from the root you drew in Question 04.4 . [1 mark] 0 4 . 6 Auxin is a plant hormone. Explain how auxin causes the results in apparatus A . [2 marks] Question 4 continues on the next page Turn over ► * 17 * IB/H/Jun24/8461/2H

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17
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Figure 6 is repeated below. box
Figure 6
The student left both sets of apparatus in a dark cupboard for 24 hours.
0 4 . 5 Describe how a root from apparatus B would look different from the root you drew
in Question 04.4 .
[1 mark]
0 4 . 6 Auxin is a plant hormone.
Explain how auxin causes the results in apparatus A .
[2 marks]
Question 4 continues on the next page
Turn over ►
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PMT 18 Do not write outside the Farmers can use plant hormones to control the growth of plants. box 0 4 . 7 Give two uses of auxin. [2 marks] 1 2 0 4 . 8 A farmer sprayed an apple tree with gibberellin. Suggest two reasons why the farmer sprayed the apple tree with gibberellin. [2 marks] 1 2 15 * 18 * IB/H/Jun24/8461/2H

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Farmers can use plant hormones to control the growth of plants. box
0 4 . 7 Give two uses of auxin.
[2 marks]
1
2
0 4 . 8 A farmer sprayed an apple tree with gibberellin.
Suggest two reasons why the farmer sprayed the apple tree with gibberellin.
[2 marks]
1
2
15
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PMT 19 Do not write outside the Turn over for the next question box DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Turn over ► * 19 * IB/H/Jun24/8461/2H

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19
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DO NOT WRITE ON THIS PAGE
ANSWER IN THE SPACES PROVIDED
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PMT 20 Do not write outside the 0 5 The human body has two coordination systems: box • the nervous system • the endocrine system. 0 5 . 1 Two students investigated human reaction time. Student A held a metre rule above student B ’s hand. Student A then released the metre rule and student B caught the rule as quickly as possible. Figure 8 shows the method used. Figure 8 Suggest two ways to improve the students’ method for measuring human reaction time. [2 marks] 1 2 * 20 * IB/H/Jun24/8461/2H

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20
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0 5 The human body has two coordination systems: box
• the nervous system
• the endocrine system.
0 5 . 1 Two students investigated human reaction time.
Student A held a metre rule above student B ’s hand.
Student A then released the metre rule and student B caught the rule as quickly as
possible.
Figure 8 shows the method used.
Figure 8
Suggest two ways to improve the students’ method for measuring
human reaction time.
[2 marks]
1
2
* 20 *
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PMT 21 Do not write outside the 0 5 . 2 Student B ’s reaction is coordinated by the nervous system. box Give two ways that coordination by the endocrine system is different from coordination by the nervous system. [2 marks] 1 2 Question 5 continues on the next page Turn over ► * 21 * IB/H/Jun24/8461/2H

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0 5 . 2 Student B ’s reaction is coordinated by the nervous system. box
Give two ways that coordination by the endocrine system is different from
coordination by the nervous system.
[2 marks]
1
2
Question 5 continues on the next page
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PMT 22 Do not write outside the Figure 9 shows endocrine glands in a female. box Figure 9 0 5 . 3 Name one hormone produced by gland A . [ 1 mark] 0 5 . 4 Name one hormone produced by gland B . [1 mark] 0 5 . 5 The adrenal gland produces the hormone adrenaline. Describe two effects of adrenaline on the human body. [2 marks] 1 2 * 22 * IB/H/Jun24/8461/2H

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22
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Figure 9 shows endocrine glands in a female. box
Figure 9
0 5 . 3 Name one hormone produced by gland A .
[ 1 mark]
0 5 . 4 Name one hormone produced by gland B .
[1 mark]
0 5 . 5 The adrenal gland produces the hormone adrenaline.
Describe two effects of adrenaline on the human body.
[2 marks]
1
2
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PMT 23 Do not write outside the 0 5 . 6 Hormones can be used for controlling human reproduction. box Explain the use of hormones in: • contraception • the treatment of infertility. [ 6 marks] 14 Turn over for the next question Turn over ► * 23 * IB/H/Jun24/8461/2H

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0 5 . 6 Hormones can be used for controlling human reproduction. box
Explain the use of hormones in:
• contraception
• the treatment of infertility.
[ 6 marks]
14
Turn over for the next question
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* 23 *
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PMT 24 Do not write outside the 0 6 Some human disorders are inherited. box Polydactyly is an inherited disorder. • A person with polydactyly has extra fingers or toes. • Polydactyly is caused by a dominant allele. 0 6 . 1 What is a dominant allele? [1 mark] Figure 10 shows the inheritance of polydactyly in one family. Figure 10 * 24 * IB/H/Jun24/8461/2H

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0 6 Some human disorders are inherited. box
Polydactyly is an inherited disorder.
• A person with polydactyly has extra fingers or toes.
• Polydactyly is caused by a dominant allele.
0 6 . 1 What is a dominant allele?
[1 mark]
Figure 10 shows the inheritance of polydactyly in one family.
Figure 10
* 24 *
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PMT 25 Do not write outside the In questions 06.2 and 06.3 , use the following symbols: box D = allele for having polydactyly d = allele for not having polydactyly. 0 6 . 2 Person 1 is heterozygous. Explain how Figure 10 shows that person 1 is heterozygous. [2 marks] 0 6 . 3 Persons 6 and 7 are expecting a fourth child. A doctor states that the probability of having a child with polydactyly is 0.5 Explain how the doctor determined this probability. [4 marks] You should: • draw a Punnett square diagram • give the genotype of person 6 and the genotype of person 7 • identify all the offspring that will have polydactyly. Question 6 continues on the next page Turn over ► * 25 * IB/H/Jun24/8461/2H

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In questions 06.2 and 06.3 , use the following symbols: box
D = allele for having polydactyly
d = allele for not having polydactyly.
0 6 . 2 Person 1 is heterozygous.
Explain how Figure 10 shows that person 1 is heterozygous.
[2 marks]
0 6 . 3 Persons 6 and 7 are expecting a fourth child.
A doctor states that the probability of having a child with polydactyly is 0.5
Explain how the doctor determined this probability.
[4 marks]
You should:
• draw a Punnett square diagram
• give the genotype of person 6 and the genotype of person 7
• identify all the offspring that will have polydactyly.
Question 6 continues on the next page
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PMT 26 Do not write outside the 0 6 . 4 Cystic fibrosis (CF) is another inherited disorder caused by a mutation. box The mutation occurs in a gene called CFTR. For the CFTR gene, one allele in every 50 in the UK population is the cystic fibrosis allele. Explain why only one person in 2500 in the UK population has cystic fibrosis. [4 marks] 11 * 26 * IB/H/Jun24/8461/2H

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26
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0 6 . 4 Cystic fibrosis (CF) is another inherited disorder caused by a mutation. box
The mutation occurs in a gene called CFTR.
For the CFTR gene, one allele in every 50 in the UK population is the cystic fibrosis
allele.
Explain why only one person in 2500 in the UK population has cystic fibrosis.
[4 marks]
11
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PMT 27 Do not write outside the 0 7 Farmers can increase the growth rate of farm animals by controlling the box animals’ diets. A farmer has 1000 chickens. • The farmer feeds the chickens on seeds from maize plants. • 1 hectare of land produces 16.4 tonnes of maize seeds. • The maize seeds have an energy content of 16 MJ per kg. • Chickens can use 80% of the energy in maize seeds. • Each chicken needs 46 MJ of energy to grow to full size. 0 7 . 1 Calculate the area of land needed to provide enough energy from maize seeds for 1000 chickens to grow to full size. Give your answer in m 2 . Give your answer to 3 significant figures. 1 hectare = 10 000 m 2 1 tonne = 1000 kg [ 5 mark s ] Area of land (3 significant figures) = m 2 Question 7 continues on the next page Turn over ► * 27 * IB/H/Jun24/8461/2H

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0 7 Farmers can increase the growth rate of farm animals by controlling the box
animals’ diets.
A farmer has 1000 chickens.
• The farmer feeds the chickens on seeds from maize plants.
• 1 hectare of land produces 16.4 tonnes of maize seeds.
• The maize seeds have an energy content of 16 MJ per kg.
• Chickens can use 80% of the energy in maize seeds.
• Each chicken needs 46 MJ of energy to grow to full size.
0 7 . 1 Calculate the area of land needed to provide enough energy from maize seeds for
1000 chickens to grow to full size.
Give your answer in m 2 .
Give your answer to 3 significant figures.
1 hectare = 10 000 m 2
1 tonne = 1000 kg
[ 5 mark s ]
Area of land (3 significant figures) = m 2
Question 7 continues on the next page
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PMT 28 Do not write outside the 0 7 . 2 Another farmer produced 4200 kg of maize seeds in a field. box The farmer fed the maize to 1000 chickens. At full size, the mean mass of one chicken was 2.2 kg. Complete Figure 11 to show a pyramid of biomass for the food chain from the maize seeds to 1000 chickens. [3 marks] You should: • label the x-axis • use a suitable scale. Figure 11 * 28 * IB/H/Jun24/8461/2H

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28
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0 7 . 2 Another farmer produced 4200 kg of maize seeds in a field. box
The farmer fed the maize to 1000 chickens.
At full size, the mean mass of one chicken was 2.2 kg.
Complete Figure 11 to show a pyramid of biomass for the food chain from the maize
seeds to 1000 chickens.
[3 marks]
You should:
• label the x-axis
• use a suitable scale.
Figure 11
* 28 *
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PMT 29 Do not write outside the 0 7 . 3 Calculate the ratio of chicken biomass to maize seed biomass. box Use data from Question 07.2 . Give your answer in its simplest form. [2 marks] : Ratio = 0 7 . 4 Chickens can use 80% of the biomass from the maize seeds they eat for respiration and growth. What happens to the remaining 20% of the biomass in the maize seeds? [ 1 mark] Question 7 continues on the next page Turn over ► * 29 * IB/H/Jun24/8461/2H

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0 7 . 3 Calculate the ratio of chicken biomass to maize seed biomass. box
Use data from Question 07.2 .
Give your answer in its simplest form.
[2 marks]
:
Ratio =
0 7 . 4 Chickens can use 80% of the biomass from the maize seeds they eat for respiration
and growth.
What happens to the remaining 20% of the biomass in the maize seeds?
[ 1 mark]
Question 7 continues on the next page
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PMT 30 Do not write outside the Protein is an important part of a chicken’s diet. box • Proteins contain 20 different types of amino acid. • A chicken can make many of the 20 amino acids from other substances in the diet. • Essential amino acids are amino acids the chicken cannot make. • Essential amino acids must be included in the diet. Maize seeds contain protein but the proportion of some essential amino acids is low. Scientists have produced a type of maize called Quality Protein Maize (QPM). Table 2 compares the proportions of seven essential amino acids in normal maize seeds and in QPM seeds. Table 2 Mass of amino acid in protein in g/kg Amino acid Normal maize Quality protein maize (QPM) Leucine 122.2 88.1 Lysine 28.9 41.9 Methionine 19.9 18.1 Phenylalanine 49.4 40.9 Threonine 34.5 36.5 Tryptophan 7.3 16.3 Valine 45.9 51.2 * 30 * IB/H/Jun24/8461/2H

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30
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Protein is an important part of a chicken’s diet. box
• Proteins contain 20 different types of amino acid.
• A chicken can make many of the 20 amino acids from other substances in the diet.
• Essential amino acids are amino acids the chicken cannot make.
• Essential amino acids must be included in the diet.
Maize seeds contain protein but the proportion of some essential amino acids is low.
Scientists have produced a type of maize called Quality Protein Maize (QPM).
Table 2 compares the proportions of seven essential amino acids in normal maize
seeds and in QPM seeds.
Table 2
Mass of amino acid in protein in g/kg
Amino acid
Normal maize Quality protein maize (QPM)
Leucine 122.2 88.1
Lysine 28.9 41.9
Methionine 19.9 18.1
Phenylalanine 49.4 40.9
Threonine 34.5 36.5
Tryptophan 7.3 16.3
Valine 45.9 51.2
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PMT 31 Do not write outside the 0 7 . 5 Which amino acids are found in significantly higher proportions in the QPM seeds? box [1 mark] Tick (  ) one box. Lysine and tryptophan Lysine and valine Threonine and tryptophan Threonine and valine 0 7 . 6 Table 2 shows that 1 kg of QPM contains less leucine than 1 kg of normal maize. Suggest why a diet containing less leucine does not slow down the growth of chickens. [1 mark] 13 Turn over for the next question Turn over ► * 31 * IB/H/Jun24/8461/2H

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31
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0 7 . 5 Which amino acids are found in significantly higher proportions in the QPM seeds? box
[1 mark]
Tick (  ) one box.
Lysine and tryptophan
Lysine and valine
Threonine and tryptophan
Threonine and valine
0 7 . 6 Table 2 shows that 1 kg of QPM contains less leucine than 1 kg of normal maize.
Suggest why a diet containing less leucine does not slow down the growth
of chickens.
[1 mark]
13
Turn over for the next question
Turn over ►
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PMT 32 Do not write outside the 0 8 Conditions inside and outside of the human body often change. box Homeostasis helps the human body to survive changing conditions. 0 8 . 1 Explain what is meant by the term ‘homeostasis’. [2 marks] The kidneys have an important role in homeostasis. 0 8 . 2 Describe what happens to glucose , protein and urea in the kidneys. [4 marks] * 32 * IB/H/Jun24/8461/2H

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0 8 Conditions inside and outside of the human body often change. box
Homeostasis helps the human body to survive changing conditions.
0 8 . 1 Explain what is meant by the term ‘homeostasis’.
[2 marks]
The kidneys have an important role in homeostasis.
0 8 . 2 Describe what happens to glucose , protein and urea in the kidneys.
[4 marks]
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PMT 33 Do not write outside the 0 8 . 3 Explain how ADH affects the production and concentration of urine by the kidneys. box [4 marks] 10 Turn over for the next question Turn over ► * 33 * IB/H/Jun24/8461/2H

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0 8 . 3 Explain how ADH affects the production and concentration of urine by the kidneys. box
[4 marks]
10
Turn over for the next question
Turn over ►
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PMT 34 Do not write outside the 0 9 Glyphosate is a herbicide used in agriculture. box Soya bean plants have been genetically modified (GM) to be resistant to glyphosate. A farmer can increase the yield of soya beans by: • growing GM soya bean plants • spraying glyphosate on the field. 0 9 . 1 Explain how the use of GM soya bean plants and glyphosate can increase the yield of soya beans. [6 marks] * 34 * IB/H/Jun24/8461/2H

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0 9 Glyphosate is a herbicide used in agriculture. box
Soya bean plants have been genetically modified (GM) to be resistant to glyphosate.
A farmer can increase the yield of soya beans by:
• growing GM soya bean plants
• spraying glyphosate on the field.
0 9 . 1 Explain how the use of GM soya bean plants and glyphosate can increase the yield
of soya beans.
[6 marks]
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PMT 35 Do not write outside the 0 9 . 2 Suggest two reasons why some people are concerned about the use of GM soya box bean plants. Do not refer to ethical concerns or religion in your answer. [2 marks] 1 2 8 END OF QUESTIONS * 35 * IB/H/Jun24/8461/2H

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0 9 . 2 Suggest two reasons why some people are concerned about the use of GM soya box
bean plants.
Do not refer to ethical concerns or religion in your answer.
[2 marks]
1
2
8
END OF QUESTIONS
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PMT 36 Do not write outside the There are no questions printed on this page box DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED * 36 * IB/H/Jun24/8461/2H

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ANSWER IN THE SPACES PROVIDED
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PMT 37 Do not write outside the box Question Additional page, if required. number Write the question numbers in the left-hand margin. * 37 * IB/H/Jun24/8461/2H

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Question Additional page, if required. box
number Write the question numbers in the left-hand margin.
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PMT 38 Do not write outside the box Question Additional page, if required. number Write the question numbers in the left-hand margin. * 38 * IB/H/Jun24/8461/2H

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Question Additional page, if required.
number Write the question numbers in the left-hand margin.
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PMT 39 Do not write outside the box Question Additional page, if required. number Write the question numbers in the left-hand margin. * 39 * IB/H/Jun24/8461/2H

PMT
39
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Question Additional page, if required. box
number Write the question numbers in the left-hand margin.
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PMT 40 Do not write outside the There are no questions printed on this page box DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Copyright information For confidentiality purposes, all acknowledgements of third-party copyright material are published in a separate booklet. This booklet is published after each live examination series and is available for free download from www.aqa.org.uk. Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright-holders may have been unsuccessful and AQA will be happy to rectify any omissions of acknowledgements. If you have any queries please contact the Copyright Team. Copyright © 2024 AQA and its licensors. All rights reserved. * 246G8461/2H * * 40 * IB/H/Jun24/8461/2H

PMT
40
Do not write
outside the
There are no questions printed on this page box
DO NOT WRITE ON THIS PAGE
ANSWER IN THE SPACES PROVIDED
Copyright information
For confidentiality purposes, all acknowledgements of third-party copyright material are published in a separate booklet. This booklet is published after
each live examination series and is available for free download from www.aqa.org.uk.
Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright-holders may have been unsuccessful
and AQA will be happy to rectify any omissions of acknowledgements. If you have any queries please contact the Copyright Team.
Copyright © 2024 AQA and its licensors. All rights reserved.
* 246G8461/2H *
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June 2024 QP