2.
1: Explain why most of the dead remains of plants in layer B do not
decay [3 marks]
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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 appropriate biomass of the moss that becomes biomass in
primary consumers? (One box) [1 marks]
0.34 g/m2/year
3.4 g/m2/year
34 g/m2/year
340 g/m2/year
0.3: Frogs are animals that lay their eggs in water. The eggs hatch as
tadpoles. Students investigated the number of tadpoles in a pond for 8
weeks.
This is the method used.
1. Collect 10dm3 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.
3.1: Suggest one improvement to the method. [1 mark]
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3.2: Value X is the number of tadpoles in sample 4, at 3 weeks
Calculate value X [1 mark]
3.3: [4 marks]
-Label X-axis
-Use a suitable scale
-Plot data for total number of tadpoles from Figure 1
-Draw a line of best fit
4.1: Give the reason why the student placed both sets of apparatus in the
dark. [1 mark]
4.2: What are two reasons for surrounding the seedlings with damp
blotting paper? [2 marks]
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
4.3: Apparatus B is a control. Explain why apparatus B is needed. [2
marks]
4.7: Give 2 uses of auxin [2 marks]
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2_________________________________________________________________________
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4.8: A farmer sprayed an apple tree with gibberellin. Suggest two reasons
why the farmer sprayed the apple tree with gibberellin. [2 marks]
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2_________________________________________________________________________
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5: The human body has 2 coordination systems:
-The nervous system
-The endocrine system
5.1: Teo 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. Suggest 2 ways to improve the students methods for
measuring human reaction time. [2 marks]
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2_________________________________________________________________________
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5.6: Hormones can be used for controlling human reproduction.
Explain the use of hormones in:
-contraception
-the treatment of infertility [6 marks]
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