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AQA AS-LEVEL BIOLOGY PAPER 2 EXAM QUESTIONS WITH
VERIFIED QUESTIONS DETAILED RATIONALES GRADED A+
AQA AS-LEVEL BIOLOGY PAPER 2
Questions with Answers and Rationales
SECTION 1: BIOLOGICAL MOLECULES IN DEPTH
Questions 1–40
1. Which of the following is a pentose sugar?
• A) Glucose
• B) Fructose
• C) Ribose
• D) Galactose
Answer: C) Ribose
Rationale: Ribose is a pentose (5-carbon) sugar. Glucose, fructose, and galactose are hexoses (6-
carbon sugars).
2. The condensation of two α-glucose molecules produces:
• A) Sucrose
• B) Maltose
• C) Lactose
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• D) Cellulose
Answer: B) Maltose
Rationale: Two α-glucose molecules condense to form maltose, a disaccharide.
3. The condensation of glucose and fructose produces:
• A) Sucrose
• B) Maltose
• C) Lactose
• D) Cellulose
Answer: A) Sucrose
Rationale: Sucrose is formed from glucose and fructose.
4. The condensation of glucose and galactose produces:
• A) Sucrose
• B) Maltose
• C) Lactose
• D) Cellulose
Answer: C) Lactose
Rationale: Lactose is formed from glucose and galactose.
5. Which of the following is a structural isomer of glucose?
• A) Sucrose
• B) Fructose
• C) Maltose
• D) Glycogen
Answer: B) Fructose
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Rationale: Fructose is a structural isomer of glucose, having the same molecular formula but a
different structure.
6. The test for a non-reducing sugar involves:
• A) Adding Benedict's solution directly
• B) Boiling with dilute HCl, neutralising, then adding Benedict's solution
• C) Adding iodine solution
• D) Adding biuret reagent
Answer: B) Boiling with dilute HCl, neutralising, then adding Benedict's solution
Rationale: Acid hydrolysis breaks the glycosidic bond, releasing reducing sugars that can be
detected.
7. Amylose is:
• A) A branched polysaccharide
• B) An unbranched polysaccharide
• C) A disaccharide
• D) A monosaccharide
Answer: B) An unbranched polysaccharide
Rationale: Amylose is an unbranched helix of α-glucose.
8. Amylopectin is:
• A) A branched polysaccharide
• B) An unbranched polysaccharide
• C) A disaccharide
• D) A monosaccharide
Answer: A) A branched polysaccharide
Rationale: Amylopectin is a branched polysaccharide of α-glucose.
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9. Cellulose is composed of:
• A) α-glucose
• B) β-glucose
• C) Fructose
• D) Galactose
Answer: B) β-glucose
Rationale: Cellulose is a polymer of β-glucose.
10. The bonds between cellulose chains are:
• A) Glycosidic bonds
• B) Hydrogen bonds
• C) Peptide bonds
• D) Ester bonds
Answer: B) Hydrogen bonds
Rationale: Hydrogen bonds form between cellulose chains, providing strength.
11. Glycogen is:
• A) A branched polysaccharide of α-glucose
• B) An unbranched polysaccharide
• C) A disaccharide
• D) A monosaccharide
Answer: A) A branched polysaccharide of α-glucose
Rationale: Glycogen is a highly branched polysaccharide of α-glucose.
12. A triglyceride is formed by:
AQA AS-LEVEL BIOLOGY PAPER 2 EXAM QUESTIONS WITH
VERIFIED QUESTIONS DETAILED RATIONALES GRADED A+
AQA AS-LEVEL BIOLOGY PAPER 2
Questions with Answers and Rationales
SECTION 1: BIOLOGICAL MOLECULES IN DEPTH
Questions 1–40
1. Which of the following is a pentose sugar?
• A) Glucose
• B) Fructose
• C) Ribose
• D) Galactose
Answer: C) Ribose
Rationale: Ribose is a pentose (5-carbon) sugar. Glucose, fructose, and galactose are hexoses (6-
carbon sugars).
2. The condensation of two α-glucose molecules produces:
• A) Sucrose
• B) Maltose
• C) Lactose
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• D) Cellulose
Answer: B) Maltose
Rationale: Two α-glucose molecules condense to form maltose, a disaccharide.
3. The condensation of glucose and fructose produces:
• A) Sucrose
• B) Maltose
• C) Lactose
• D) Cellulose
Answer: A) Sucrose
Rationale: Sucrose is formed from glucose and fructose.
4. The condensation of glucose and galactose produces:
• A) Sucrose
• B) Maltose
• C) Lactose
• D) Cellulose
Answer: C) Lactose
Rationale: Lactose is formed from glucose and galactose.
5. Which of the following is a structural isomer of glucose?
• A) Sucrose
• B) Fructose
• C) Maltose
• D) Glycogen
Answer: B) Fructose
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Rationale: Fructose is a structural isomer of glucose, having the same molecular formula but a
different structure.
6. The test for a non-reducing sugar involves:
• A) Adding Benedict's solution directly
• B) Boiling with dilute HCl, neutralising, then adding Benedict's solution
• C) Adding iodine solution
• D) Adding biuret reagent
Answer: B) Boiling with dilute HCl, neutralising, then adding Benedict's solution
Rationale: Acid hydrolysis breaks the glycosidic bond, releasing reducing sugars that can be
detected.
7. Amylose is:
• A) A branched polysaccharide
• B) An unbranched polysaccharide
• C) A disaccharide
• D) A monosaccharide
Answer: B) An unbranched polysaccharide
Rationale: Amylose is an unbranched helix of α-glucose.
8. Amylopectin is:
• A) A branched polysaccharide
• B) An unbranched polysaccharide
• C) A disaccharide
• D) A monosaccharide
Answer: A) A branched polysaccharide
Rationale: Amylopectin is a branched polysaccharide of α-glucose.
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9. Cellulose is composed of:
• A) α-glucose
• B) β-glucose
• C) Fructose
• D) Galactose
Answer: B) β-glucose
Rationale: Cellulose is a polymer of β-glucose.
10. The bonds between cellulose chains are:
• A) Glycosidic bonds
• B) Hydrogen bonds
• C) Peptide bonds
• D) Ester bonds
Answer: B) Hydrogen bonds
Rationale: Hydrogen bonds form between cellulose chains, providing strength.
11. Glycogen is:
• A) A branched polysaccharide of α-glucose
• B) An unbranched polysaccharide
• C) A disaccharide
• D) A monosaccharide
Answer: A) A branched polysaccharide of α-glucose
Rationale: Glycogen is a highly branched polysaccharide of α-glucose.
12. A triglyceride is formed by:
