Tuesday 16 June 2026 – Morning
A Level Biology A
H420/03 Unified biology
Time allowed: 1 hour 30 minutes
You can use:
*
• a scientific or graphical calculator
• a ruler (cm/mm)
* H 4 2 0 0 3 *
*
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.
Cambridge OCR 2026 [601/4260/1] Cambridge OCR is an exempt Charity
DC (CJ/TC) 359628/4 Turn over
, 2
BLANK PAGE
DO NOT WRITE ON THIS PAGE
Cambridge OCR 2026
, 3
1 The liver is an organ with many roles.
(a) The transmission electron micrograph shows a section through liver tissue.
An adult human liver contains millions of the blood vessel labelled B. Blood flows from an
arteriole and a hepatic portal venule into these blood vessels.
Hepatocyte
A
×1800
B
Name the cell labelled A and the blood vessel labelled B.
A .......................................................................................................................................................
B .......................................................................................................................................................
[2]
(b) Outline the role of the liver in carbohydrate metabolism.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..................................................................................................................................................... [2]
Cambridge OCR 2026 Turn over
A Level Biology A
H420/03 Unified biology
Time allowed: 1 hour 30 minutes
You can use:
*
• a scientific or graphical calculator
• a ruler (cm/mm)
* H 4 2 0 0 3 *
*
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.
Cambridge OCR 2026 [601/4260/1] Cambridge OCR is an exempt Charity
DC (CJ/TC) 359628/4 Turn over
, 2
BLANK PAGE
DO NOT WRITE ON THIS PAGE
Cambridge OCR 2026
, 3
1 The liver is an organ with many roles.
(a) The transmission electron micrograph shows a section through liver tissue.
An adult human liver contains millions of the blood vessel labelled B. Blood flows from an
arteriole and a hepatic portal venule into these blood vessels.
Hepatocyte
A
×1800
B
Name the cell labelled A and the blood vessel labelled B.
A .......................................................................................................................................................
B .......................................................................................................................................................
[2]
(b) Outline the role of the liver in carbohydrate metabolism.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..................................................................................................................................................... [2]
Cambridge OCR 2026 Turn over
