OCR AS LEVEL JUNE 2023_2024
BIOLOGY B H022/02 PAPER 2 QUESTION PAPER
Oxford Cambridge and RSA
Thursday 9 June 2022 – Afternoon
AS Level
... [Show More] Biology B (Advancing Biology)
H022/02 Biology in depth
Time allowed: 1 hour 30 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 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 2022 [601/4721/0] DC (ST/JG) 300559/3
OCR is an exempt Charity
Turn over
Answer all the questions.
1 Fig. 1.1 shows a prepared slide of onion cells in different stages of mitosis, viewed using a light microscope.
A B
C
Fig. 1.1
(a) (i) Name the stages of mitosis taking place in cells A and B.
A ............................................................................................................................. ...........
B ........................................................................................................................................
[2]
(ii) Fig. 1.2 shows a student’s drawing of the cell labelled C in Fig. 1.1.
Fig. 1.2
Give two improvements the student could make to their drawing.
1 ............................................................................................................................. ...........
...........................................................................................................................................
2 ............................................................................................................................. ...........
............................................................................................. ..............................................
[2]
(b) Fig. 1.3 shows the cell cycle in an onion cell.
G1 checkpoint
Fig. 1.3
Mitosis in an onion cell occurs once in 24 hours and lasts for 80 minutes. Metaphase takes approximately 6.5 minutes to complete.
Calculate the percentage of the cell cycle which is spent in metaphase.
Metaphase = % [2]
(c) There are two main checkpoints in the cell cycle, the G1 checkpoint and the G2 checkpoint.
Explain how each of the checkpoints can ensure the cell develops normally.
G1 ............................................................................................................................. ................
...................................................................................................................................................
G2 ............................................................................................................................. ................
...................................................................................................................................................
[2]
(d) The cell cycle is controlled by proteins. These proteins can initiate apoptosis.
Describe the sequence of events that occurs during apoptosis.
............................................................................................................................. ......................
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