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Thursday 23 May 2024 – Morning
AS Level Biology A
H020/02 Depth in biology
Time allowed: 1 hour 30 minutes
You can use:
a scientific or graphical calculator
a ruler (cm/mm)
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 70.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 24 pages.
ADVICE
• Read each question carefully before you start your answer.
Turn over
, 2
1
(a) Students used a transect line to sample species of wildflowers in a field.
(i) Name the type of sampling method used in a transect line.
................................................................................................................................................... [1]
(ii) This table shows their findings.
Number of
Species organisms n/N (n / N)2
(n)
Foxglove 3 0.13 0.02
Meadow buttercup 7
Oxeye daisy 9
Yellow rattle 4
N= ∑(n / N)2 =
1 – ∑(n / N)2 =
Calculate the Simpson’s Index of Diversity for the field using the data in the above table.
n
Use the formula: D = 1 – d∑bN l2n
Give your answer to 2 significant figures.
Simpson’s Index of Diversity =...........................................................[3]
(iii) State what can be concluded about the diversity of the field from your answer in (a)(ii).
..........................................................................................................................................................
................................................................................................................................................... [1]
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, 3
(b) The students then used a sweep net to sample animals in two different parts of a river.
They did this by holding the sweep net in the water and at the same time kicking the riverbed
downstream.
Suggest how they could improve their sampling method to obtain more valid results.
..........................................................................................................................................................
................................................................................................................................................... [1]
(c) Black oak trees are an example of a keystone species within an oak woodland ecosystem in
England.
Suggest what would happen to the ecosystem if the black oak trees died out.
..........................................................................................................................................................
................................................................................................................................................... [1]
verified Turn over
Thursday 23 May 2024 – Morning
AS Level Biology A
H020/02 Depth in biology
Time allowed: 1 hour 30 minutes
You can use:
a scientific or graphical calculator
a ruler (cm/mm)
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 70.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 24 pages.
ADVICE
• Read each question carefully before you start your answer.
Turn over
, 2
1
(a) Students used a transect line to sample species of wildflowers in a field.
(i) Name the type of sampling method used in a transect line.
................................................................................................................................................... [1]
(ii) This table shows their findings.
Number of
Species organisms n/N (n / N)2
(n)
Foxglove 3 0.13 0.02
Meadow buttercup 7
Oxeye daisy 9
Yellow rattle 4
N= ∑(n / N)2 =
1 – ∑(n / N)2 =
Calculate the Simpson’s Index of Diversity for the field using the data in the above table.
n
Use the formula: D = 1 – d∑bN l2n
Give your answer to 2 significant figures.
Simpson’s Index of Diversity =...........................................................[3]
(iii) State what can be concluded about the diversity of the field from your answer in (a)(ii).
..........................................................................................................................................................
................................................................................................................................................... [1]
verified
, 3
(b) The students then used a sweep net to sample animals in two different parts of a river.
They did this by holding the sweep net in the water and at the same time kicking the riverbed
downstream.
Suggest how they could improve their sampling method to obtain more valid results.
..........................................................................................................................................................
................................................................................................................................................... [1]
(c) Black oak trees are an example of a keystone species within an oak woodland ecosystem in
England.
Suggest what would happen to the ecosystem if the black oak trees died out.
..........................................................................................................................................................
................................................................................................................................................... [1]
verified Turn over
