OCR
GCE
Biology B
H022/02: Biology in depth
AS Level
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 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.
© OCR 2025 [601/4721/0] DC (LK/CB) 329634/3
OCR is an exempt Charity
Turn over
1
(a) The mammalian circulatory system is described as a closed double circulatory system.
(i) Explain what is meant by a closed circulatory system.
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(ii) The diagram below shows the circulatory system of a frog.
, 2
Capillaries in the lungs and skin
Capillaries in the muscles
Blood leaving the heart of a frog is less oxygenated than blood leaving the heart of a
mammal.
Explain why blood leaving the heart of a frog is less oxygenated than blood leaving
the heart of a mammal.
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(b) The image below shows a section through the wall of an artery.
© OCR 2025
, 3
X Y
×500
Calculate the actual width of the artery wall between points X and Y.
Give your answer to the nearest whole number.
Actual width = ................................................... μm [2] (c)* Describe how the
tissues in the artery wall are adapted to their function.
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© OCR 2025 Turn over
, 4
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Extra answer space if required.
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© OCR 2025
GCE
Biology B
H022/02: Biology in depth
AS Level
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 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.
© OCR 2025 [601/4721/0] DC (LK/CB) 329634/3
OCR is an exempt Charity
Turn over
1
(a) The mammalian circulatory system is described as a closed double circulatory system.
(i) Explain what is meant by a closed circulatory system.
......................................................................................................................................
....................
......................................................................................................................................
............... [1]
(ii) The diagram below shows the circulatory system of a frog.
, 2
Capillaries in the lungs and skin
Capillaries in the muscles
Blood leaving the heart of a frog is less oxygenated than blood leaving the heart of a
mammal.
Explain why blood leaving the heart of a frog is less oxygenated than blood leaving
the heart of a mammal.
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
............... [2]
(b) The image below shows a section through the wall of an artery.
© OCR 2025
, 3
X Y
×500
Calculate the actual width of the artery wall between points X and Y.
Give your answer to the nearest whole number.
Actual width = ................................................... μm [2] (c)* Describe how the
tissues in the artery wall are adapted to their function.
......................................................................................................................................
....................
......................................................................................................................................
....................
......................................................................................................................................
....................
© OCR 2025 Turn over
, 4
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........... ...................................................................................................................................
.................. [6]
Extra answer space if required.
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© OCR 2025
