Oxford Cambridge and RSA
Tuesday 16 May 2023 – Morning
GCSE (9–1) Biology B
(Twenty First Century Science)
J257/03 Breadth in biology (Higher
... [Show More] Tier)
Time allowed: 1 hour 45 minutes
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 90.
• The marks for each question are shown in brackets [ ].
• This document has 24 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2023 [601/8506/5]
DC (PQ/JG) 329298/3
OCR is an exempt Charity
Turn over
You
• a ruler
must
(cm/mm)
have: H
You can use:
• an HB pencil
• a scientific or graphical calculator
2
© OCR 2023
1 (a) (i) Complete the table to compare cellular aerobic and anaerobic respiration in humans.
Tick (✓) the correct boxes in each row.
[3]
(ii) Which statement about respiration is correct?
Tick (✓) one box.
Aerobic respiration produces more ATP than anaerobic respiration.
Anaerobic respiration produces more ATP than aerobic respiration.
Both aerobic and anaerobic respiration produce the same amount of ATP.
Neither aerobic or anaerobic respiration produces ATP.
[1]
(b) Heart muscle contains approximately 5000 mitochondria in every cell.
(i) Suggest why heart muscle cells need so many mitochondria.
...........................................................................................................................................
...........................................................................................................................................
. ..................................................................................................................................[2]
(ii) The image shows the mitochondria in a section of heart muscle. The mitochondria are
different sizes.
One of the mitochondria is labelled.
A mitochondria
Estimate the number of mitochondria in this image.
Number of mitochondria =...........................................................[1]
Process It requires
glucose
It requires
oxygen
It produces
carbon dioxide
It produces
water
It produces
lactic acid
Aerobic
respiration
Anaerobic
respiration
3
© OCR 2023 Turn over
2 The table shows the percentage of land covered in rainforest in a country.
Year Percentage of land
covered in rainforest (%)
1940 75
1950 72
1961 53
1977 31
1983 26
1987 21
1997 42
2000 45
2005 50
(a) (i) Describe the trend in the data.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
. ..................................................................................................................................[2]
(ii) The government of the country started to protect areas of the rainforest and even paid
people to regrow it.
Suggest when the government [Show Less]