Oxford Cambridge and
RSA Examinations
GCEBiology AH420/02:
Biological diversityA
Level with Marking
scheme attached
, Oxford Cambridge and RSA
Friday 16 June 2023 – Morning
A Level Biology A
H420/02 Biological diversity
Time allowed: 2 hours 15 minutes
You can use:
* 9 8 9 7 2 2 5 1 4 6 *
• a scientific or graphical calculator
• a ruler (cm/mm)
* H 4 2 0 0 2 *
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 100.
• 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 32 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2023 [601/4260/1] OCR is an exempt Charity
DC (RW/CT) 316161/5 Turn over
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
1 Which option correctly describes a tissue?
A A group of cells performing similar functions
B A group of organs performing a specific function
C A group of similar cells performing a specific function
D A group of similar cells performing a variety of functions
Your answer [1]
2 Bone marrow stem cells are a source of erythrocytes.
Which statement about bone marrow stem cells and their role in the production of erythrocytes is
correct?
A Bone marrow stem cells are totipotent and can therefore differentiate into any type of cell.
B Erythrocytes are the only blood cell produced from bone marrow stem cells.
C Erythrocytes need to be replaced from bone marrow stem cells because erythrocytes are
unable to undergo mitosis.
D In humans, differentiation of bone marrow stem cells into erythrocytes involves the synthesis
of a haploid nucleus.
Your answer [1]
© OCR 2023
, 3
3 Which option correctly describes the sequence of events during the cell cycle?
A Cytokinesis interphase G1 G2 S mitosis
B Cytokinesis mitosis interphase
C G2 mitosis cytokinesis G1 S
D Mitosis interphase cytokinesis
Your answer [1]
4 Scientists crossed two plants that were heterozygous for two different genes. Both plants had the
same genotype, AaBb.
The genotypes and ratios of the offspring resulting from this cross were:
AABB AaBb aabb
1 : 2 : 1
Which option could explain these observations?
A Autosomal linkage
B Crossing over
C Epistasis
D Mutation
Your answer [1]
© OCR 2023 Turn over
RSA Examinations
GCEBiology AH420/02:
Biological diversityA
Level with Marking
scheme attached
, Oxford Cambridge and RSA
Friday 16 June 2023 – Morning
A Level Biology A
H420/02 Biological diversity
Time allowed: 2 hours 15 minutes
You can use:
* 9 8 9 7 2 2 5 1 4 6 *
• a scientific or graphical calculator
• a ruler (cm/mm)
* H 4 2 0 0 2 *
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 100.
• 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 32 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2023 [601/4260/1] OCR is an exempt Charity
DC (RW/CT) 316161/5 Turn over
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
1 Which option correctly describes a tissue?
A A group of cells performing similar functions
B A group of organs performing a specific function
C A group of similar cells performing a specific function
D A group of similar cells performing a variety of functions
Your answer [1]
2 Bone marrow stem cells are a source of erythrocytes.
Which statement about bone marrow stem cells and their role in the production of erythrocytes is
correct?
A Bone marrow stem cells are totipotent and can therefore differentiate into any type of cell.
B Erythrocytes are the only blood cell produced from bone marrow stem cells.
C Erythrocytes need to be replaced from bone marrow stem cells because erythrocytes are
unable to undergo mitosis.
D In humans, differentiation of bone marrow stem cells into erythrocytes involves the synthesis
of a haploid nucleus.
Your answer [1]
© OCR 2023
, 3
3 Which option correctly describes the sequence of events during the cell cycle?
A Cytokinesis interphase G1 G2 S mitosis
B Cytokinesis mitosis interphase
C G2 mitosis cytokinesis G1 S
D Mitosis interphase cytokinesis
Your answer [1]
4 Scientists crossed two plants that were heterozygous for two different genes. Both plants had the
same genotype, AaBb.
The genotypes and ratios of the offspring resulting from this cross were:
AABB AaBb aabb
1 : 2 : 1
Which option could explain these observations?
A Autosomal linkage
B Crossing over
C Epistasis
D Mutation
Your answer [1]
© OCR 2023 Turn over
