AQA A Level Biology Paper 1 Latest Update
2026 |A Comprehensive Review of 300
Multiple-Choice Question Bank with
Answers and Detailed Rationale| Guaranteed
Pass
Introduction
This comprehensive question bank contains 300 multiple-choice questions
covering the complete AQA A Level Biology Paper 1 specification. Each question
is designed to test your understanding of key biological concepts, from biological
molecules and cell structure to transport mechanisms and the immune system. The
questions are organized to follow the progression of the specification, allowing you
to systematically test and reinforce your knowledge. Each question includes four
answer options (A, B, C, D), the correct answer, and a detailed rationale explaining
why the correct answer is right and why the distractors are wrong.
Section A: Biological Molecules
Question 1
What type of reaction joins two monomers together to form a chemical bond?
A) Hydrolysis
B) Condensation
C) Oxidation
D) Reduction
Answer: B) Condensation
Rationale: A condensation reaction joins two molecules together by forming a
chemical bond and releasing a molecule of water. This is the process by which
,monomers are joined to form polymers (e.g., joining amino acids to form proteins).
Hydrolysis is the opposite reaction (breaking bonds by adding water). Oxidation
and reduction are redox reactions that involve electron transfer, not bond
formation between monomers.
Question 2
Which process involves the addition of water to break a chemical bond between
two molecules?
A) Condensation
B) Dehydration synthesis
C) Hydrolysis
D) Phosphorylation
Answer: C) Hydrolysis
Rationale: Hydrolysis literally means "splitting with water." This process breaks
chemical bonds by adding a water molecule. It is used to break down polymers into
monomers. Condensation and dehydration synthesis are alternative terms for the
same process (joining molecules with water removal). Phosphorylation is the
addition of a phosphate group to a molecule.
Question 3
Which carbohydrate is a non-reducing sugar?
A) Glucose
B) Maltose
C) Fructose
D) Sucrose
Answer: D) Sucrose
Rationale: Sucrose is the only common non-reducing disaccharide sugar. It does
not have a free aldehyde or ketone group, so it cannot reduce Benedict's reagent.
Glucose and fructose are monosaccharides that are reducing sugars. Maltose is a
,reducing disaccharide because it has a free anomeric carbon that can reduce
Benedict's reagent.
Question 4
What is the correct sequence for testing for reducing sugars?
A) Add Benedict's reagent, heat in water bath at 95°C for 5 minutes, observe
colour change
B) Add iodine solution, heat in water bath at 95°C for 5 minutes, observe colour
change
C) Add Benedict's reagent, shake for 1 minute, observe colour change
D) Add ethanol, add water, observe colour change
Answer: A) Add Benedict's reagent, heat in water bath at 95°C for 5 minutes,
observe colour change
Rationale: The reducing sugar test involves adding Benedict's reagent (blue) to the
sample, then heating in a water bath at 95°C for 5 minutes. A positive result gives
a colour change from blue to green, yellow, orange, or brick red depending on the
concentration of reducing sugar present. Option B describes the starch test
(iodine). Option C describes the emulsion test for lipids (ethanol). Option D is
incorrect as no shaking or water addition is involved in the reducing sugar test.
Question 5
Which of the following correctly describes the test for non-reducing sugars?
A) Add Benedict's reagent directly to the sample and heat
B) Add HCl, heat, neutralize with NaHCO₃, then add Benedict's reagent and heat
C) Add ethanol, shake, then add water
D) Add biuret reagent and observe colour change
Answer: B) Add HCl, heat, neutralize with NaHCO₃, then add Benedict's
reagent and heat
Rationale: To test for non-reducing sugars, the sample must first be hydrolysed by
adding dilute HCl and heating. This breaks the glycosidic bonds, releasing
, reducing sugars. The solution is then neutralized with NaHCO₃ before adding
Benedict's reagent and heating. Option A describes the test for reducing sugars.
Option C describes the lipid emulsion test. Option D describes the protein test
using biuret reagent.
Question 6
What colour change indicates the presence of starch?
A) Blue to brick red
B) Blue to purple
C) Brown to blue-black
D) Purple to mauve
Answer: C) Brown to blue-black
Rationale: Iodine solution is brown/yellowish-orange. When added to starch, it
forms a complex that turns blue-black. This is a specific test for starch. Option A
describes the positive result for reducing sugars with Benedict's reagent. Option B
describes the biuret test for proteins. Option D is incorrect as biuret reagent
changes from blue to mauve/purple in the presence of protein.
Question 7
What is the sequence of steps for the lipid emulsion test?
A) Add Benedict's reagent, heat, observe colour change
B) Mix test solution with ethanol, shake for 1 minute, add water, look for cloudy
white emulsion
C) Add iodine solution, observe colour change
D) Add biuret reagent, observe colour change
Answer: B) Mix test solution with ethanol, shake for 1 minute, add water, look
for cloudy white emulsion
Rationale: The lipid emulsion test involves mixing the sample with ethanol to
dissolve lipids, shaking for about 1 minute, then adding water. A positive result is a
2026 |A Comprehensive Review of 300
Multiple-Choice Question Bank with
Answers and Detailed Rationale| Guaranteed
Pass
Introduction
This comprehensive question bank contains 300 multiple-choice questions
covering the complete AQA A Level Biology Paper 1 specification. Each question
is designed to test your understanding of key biological concepts, from biological
molecules and cell structure to transport mechanisms and the immune system. The
questions are organized to follow the progression of the specification, allowing you
to systematically test and reinforce your knowledge. Each question includes four
answer options (A, B, C, D), the correct answer, and a detailed rationale explaining
why the correct answer is right and why the distractors are wrong.
Section A: Biological Molecules
Question 1
What type of reaction joins two monomers together to form a chemical bond?
A) Hydrolysis
B) Condensation
C) Oxidation
D) Reduction
Answer: B) Condensation
Rationale: A condensation reaction joins two molecules together by forming a
chemical bond and releasing a molecule of water. This is the process by which
,monomers are joined to form polymers (e.g., joining amino acids to form proteins).
Hydrolysis is the opposite reaction (breaking bonds by adding water). Oxidation
and reduction are redox reactions that involve electron transfer, not bond
formation between monomers.
Question 2
Which process involves the addition of water to break a chemical bond between
two molecules?
A) Condensation
B) Dehydration synthesis
C) Hydrolysis
D) Phosphorylation
Answer: C) Hydrolysis
Rationale: Hydrolysis literally means "splitting with water." This process breaks
chemical bonds by adding a water molecule. It is used to break down polymers into
monomers. Condensation and dehydration synthesis are alternative terms for the
same process (joining molecules with water removal). Phosphorylation is the
addition of a phosphate group to a molecule.
Question 3
Which carbohydrate is a non-reducing sugar?
A) Glucose
B) Maltose
C) Fructose
D) Sucrose
Answer: D) Sucrose
Rationale: Sucrose is the only common non-reducing disaccharide sugar. It does
not have a free aldehyde or ketone group, so it cannot reduce Benedict's reagent.
Glucose and fructose are monosaccharides that are reducing sugars. Maltose is a
,reducing disaccharide because it has a free anomeric carbon that can reduce
Benedict's reagent.
Question 4
What is the correct sequence for testing for reducing sugars?
A) Add Benedict's reagent, heat in water bath at 95°C for 5 minutes, observe
colour change
B) Add iodine solution, heat in water bath at 95°C for 5 minutes, observe colour
change
C) Add Benedict's reagent, shake for 1 minute, observe colour change
D) Add ethanol, add water, observe colour change
Answer: A) Add Benedict's reagent, heat in water bath at 95°C for 5 minutes,
observe colour change
Rationale: The reducing sugar test involves adding Benedict's reagent (blue) to the
sample, then heating in a water bath at 95°C for 5 minutes. A positive result gives
a colour change from blue to green, yellow, orange, or brick red depending on the
concentration of reducing sugar present. Option B describes the starch test
(iodine). Option C describes the emulsion test for lipids (ethanol). Option D is
incorrect as no shaking or water addition is involved in the reducing sugar test.
Question 5
Which of the following correctly describes the test for non-reducing sugars?
A) Add Benedict's reagent directly to the sample and heat
B) Add HCl, heat, neutralize with NaHCO₃, then add Benedict's reagent and heat
C) Add ethanol, shake, then add water
D) Add biuret reagent and observe colour change
Answer: B) Add HCl, heat, neutralize with NaHCO₃, then add Benedict's
reagent and heat
Rationale: To test for non-reducing sugars, the sample must first be hydrolysed by
adding dilute HCl and heating. This breaks the glycosidic bonds, releasing
, reducing sugars. The solution is then neutralized with NaHCO₃ before adding
Benedict's reagent and heating. Option A describes the test for reducing sugars.
Option C describes the lipid emulsion test. Option D describes the protein test
using biuret reagent.
Question 6
What colour change indicates the presence of starch?
A) Blue to brick red
B) Blue to purple
C) Brown to blue-black
D) Purple to mauve
Answer: C) Brown to blue-black
Rationale: Iodine solution is brown/yellowish-orange. When added to starch, it
forms a complex that turns blue-black. This is a specific test for starch. Option A
describes the positive result for reducing sugars with Benedict's reagent. Option B
describes the biuret test for proteins. Option D is incorrect as biuret reagent
changes from blue to mauve/purple in the presence of protein.
Question 7
What is the sequence of steps for the lipid emulsion test?
A) Add Benedict's reagent, heat, observe colour change
B) Mix test solution with ethanol, shake for 1 minute, add water, look for cloudy
white emulsion
C) Add iodine solution, observe colour change
D) Add biuret reagent, observe colour change
Answer: B) Mix test solution with ethanol, shake for 1 minute, add water, look
for cloudy white emulsion
Rationale: The lipid emulsion test involves mixing the sample with ethanol to
dissolve lipids, shaking for about 1 minute, then adding water. A positive result is a
