Oxford Cambridge and RSA
A Level Biology A
H420/02 Biological diversity
Time allowed: 2 hours 15 minutes
You can use:
a scientific or graphical calculator
a ruler (cm/mm)
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 36 pages.
ADVICE
• Read each question carefully before you start your answer.
Turn over
for more papers: tyrionpapers.com
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
Answer all the questions.
1 Amylose differs from amylopectin in its structure because amylose
A Contains 1-6 glycosidic bonds creating a branched structure
B Is formed only from 1-4 glycosidic bonds creating a helix
C Contains pentose sugars instead of hexose sugars
D Forms through hydrolysis reactions rather than condensation
Your answer [1]
2 The enzyme responsible for forming phosphodiester bonds between RNA nucleotides
during transcription is:
A DNA helicase
B DNA polymerase
C RNA polymerase
D Ligase
Your answer [1]
3 Which of the following statements about enzyme activity in the human digestive
system is CORRECT?
A Amylase works optimally at pH 1-2 in the stomach
B Pepsin denatures when it enters the small intestine due to the alkaline pH
C Trypsin and lipase work in acidic conditions in the duodenum
D Salivary amylase continues to function effectively in the stomach
Your answer [1]
for more papers: tyrionpapers.com
, 3
4 Which statement correctly describes the difference between channel proteins and
carrier proteins?
A Channel proteins require ATP, while carrier proteins do not
B Channel proteins change shape during transport, while carrier proteins remain static
C Channel proteins allow passive diffusion through a hydrophilic pore, while carrier
proteins can be involved in both passive and active transport
D Channel proteins only transport ions, while carrier proteins only transport glucose
Your answer [1]
5 Which of the following events occurs during prophase but NOT during interphase?
A DNA replication
B Chromatin fibres condense to form visible chromosomes
C Centrioles replicate
D Protein synthesis in the nucleolus
Your answer [1]
6 Which of the following is a genetic cause of variation rather than an environmental
cause?
A Scars from a boat propeller on a manatee
B Independent assortment during meiosis
C Sun exposure causing skin darkening
D Exercise increasing muscle mass
Your answer [1]
for more papers: tyrionpapers.com
, 4
7 Why would the loss of non-drought-resistant plant species lead to the loss of some
animal species under climate change?
A Animals will overheat in warmer temperatures
B Animals dependent on these plants as a food source will decline and may be
replaced by species that feed on drought-resistant xerophytes
C All animals will migrate to polar regions
D Animals will evolve resistance to drought immediately
Your answer [1]
8 Why does callose deposition in plasmodesmata and sieve plates help prevent
pathogen spread?
A It makes cells more permeable to allow immune cells to enter
B It has no effect on pathogen spread
C It attracts beneficial bacteria to fight pathogens
D It blocks connections between cells, sealing off infected parts and preventing
pathogens from moving through plant vascular system
Your answer [1]
for more papers: tyrionpapers.com
A Level Biology A
H420/02 Biological diversity
Time allowed: 2 hours 15 minutes
You can use:
a scientific or graphical calculator
a ruler (cm/mm)
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 36 pages.
ADVICE
• Read each question carefully before you start your answer.
Turn over
for more papers: tyrionpapers.com
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
Answer all the questions.
1 Amylose differs from amylopectin in its structure because amylose
A Contains 1-6 glycosidic bonds creating a branched structure
B Is formed only from 1-4 glycosidic bonds creating a helix
C Contains pentose sugars instead of hexose sugars
D Forms through hydrolysis reactions rather than condensation
Your answer [1]
2 The enzyme responsible for forming phosphodiester bonds between RNA nucleotides
during transcription is:
A DNA helicase
B DNA polymerase
C RNA polymerase
D Ligase
Your answer [1]
3 Which of the following statements about enzyme activity in the human digestive
system is CORRECT?
A Amylase works optimally at pH 1-2 in the stomach
B Pepsin denatures when it enters the small intestine due to the alkaline pH
C Trypsin and lipase work in acidic conditions in the duodenum
D Salivary amylase continues to function effectively in the stomach
Your answer [1]
for more papers: tyrionpapers.com
, 3
4 Which statement correctly describes the difference between channel proteins and
carrier proteins?
A Channel proteins require ATP, while carrier proteins do not
B Channel proteins change shape during transport, while carrier proteins remain static
C Channel proteins allow passive diffusion through a hydrophilic pore, while carrier
proteins can be involved in both passive and active transport
D Channel proteins only transport ions, while carrier proteins only transport glucose
Your answer [1]
5 Which of the following events occurs during prophase but NOT during interphase?
A DNA replication
B Chromatin fibres condense to form visible chromosomes
C Centrioles replicate
D Protein synthesis in the nucleolus
Your answer [1]
6 Which of the following is a genetic cause of variation rather than an environmental
cause?
A Scars from a boat propeller on a manatee
B Independent assortment during meiosis
C Sun exposure causing skin darkening
D Exercise increasing muscle mass
Your answer [1]
for more papers: tyrionpapers.com
, 4
7 Why would the loss of non-drought-resistant plant species lead to the loss of some
animal species under climate change?
A Animals will overheat in warmer temperatures
B Animals dependent on these plants as a food source will decline and may be
replaced by species that feed on drought-resistant xerophytes
C All animals will migrate to polar regions
D Animals will evolve resistance to drought immediately
Your answer [1]
8 Why does callose deposition in plasmodesmata and sieve plates help prevent
pathogen spread?
A It makes cells more permeable to allow immune cells to enter
B It has no effect on pathogen spread
C It attracts beneficial bacteria to fight pathogens
D It blocks connections between cells, sealing off infected parts and preventing
pathogens from moving through plant vascular system
Your answer [1]
for more papers: tyrionpapers.com
