Part 4 — Carbohydrates: Monosaccharides, Disaccharides, Polysaccharides, Tests & Functions (Q76–100)

Q76.

Which of the following is a hexose sugar?
A. Ribose
B. Glucose ✅
C. Deoxyribose
D. Glyceraldehyde

Explanation:

A. Ribose: Pentose sugar.
B. Glucose (Correct): C₆H₁₂O₆, a six-carbon hexose sugar.
C. Deoxyribose: Pentose sugar in DNA.
D. Glyceraldehyde: A triose sugar.

Q77.

Fructose is structurally a:
A. Aldose hexose
B. Ketose hexose ✅
C. Aldose pentose
D. Ketose pentose

Explanation:

A. Aldose hexose: Applies to glucose.
B. Ketose hexose (Correct): Fructose has a ketone group at C2.
C. Aldose pentose: Ribose.
D. Ketose pentose: Rare, not fructose.

Q78.

Which sugar is a common transport form of carbohydrates in plants?
A. Glucose
B. Sucrose ✅
C. Fructose
D. Maltose

Explanation:

A. Glucose: Transport in animals, not plants.
B. Sucrose (Correct): Main transport sugar in phloem sap.
C. Fructose: Storage in some fruits.
D. Maltose: Intermediate of starch digestion.

Q79.

Which disaccharide is composed of glucose + galactose?
A. Sucrose
B. Lactose ✅
C. Maltose
D. Trehalose

Explanation:

A. Sucrose: Glucose + fructose.
B. Lactose (Correct): Milk sugar = glucose + galactose.
C. Maltose: Glucose + glucose.
D. Trehalose: Glucose + glucose (fungal sugar).

Q80.

Which carbohydrate test gives a purple ring at the junction of two layers?
A. Benedict’s test
B. Molisch’s test ✅
C. Iodine test
D. Fehling’s test

Explanation:

**A. Benedict’s: reducing sugars → brick-red ppt.
B. Molisch’s (Correct): General test for carbohydrates using α-naphthol and conc. H₂SO₄ → purple ring.
**C. Iodine: starch (blue-black).
**D. Fehling’s: reducing sugars.

Q81.

Which is the storage polysaccharide in plants?
A. Cellulose
B. Starch ✅
C. Glycogen
D. Chitin

Explanation:

A. Cellulose: Structural in plant cell wall.
B. Starch (Correct): Storage form (amylose + amylopectin).
**C. Glycogen: storage in animals.
**D. Chitin: structural in fungi and arthropods.

Q82.

Which polysaccharide is the major component of plant cell walls?
A. Starch
B. Glycogen
C. Cellulose ✅
D. Inulin

Explanation:

**A. Starch: storage.
**B. Glycogen: animal storage.
C. Cellulose (Correct): Structural, β-1,4 linked glucose.
**D. Inulin: storage in dahlia/tuber crops.

Q83.

Which sugar gives a positive Benedict’s test?
A. Sucrose
B. Glucose ✅
C. Cellulose
D. Starch

Explanation:

**A. Sucrose: non-reducing sugar.
B. Glucose (Correct): Reducing sugar → brick-red ppt.
**C. Cellulose: non-reducing polysaccharide.
**D. Starch: gives iodine test, not Benedict’s.

Q84.

Which sugar is known as “fruit sugar”?
A. Glucose
B. Fructose ✅
C. Sucrose
D. Maltose

Explanation:

**A. Glucose: blood sugar.
B. Fructose (Correct): Found abundantly in fruits.
**C. Sucrose: table sugar.
**D. Maltose: malt sugar.

Q85.

Which disaccharide is non-reducing?
A. Maltose
B. Lactose
C. Sucrose ✅
D. Cellobiose

Explanation:

**A. Maltose: reducing.
**B. Lactose: reducing.
C. Sucrose (Correct): No free aldehyde/ketone → non-reducing.
**D. Cellobiose: reducing.

Q86.

Which is the storage polysaccharide in animals?
A. Glycogen ✅
B. Cellulose
C. Starch
D. Chitin

Explanation:

A. Glycogen (Correct): Highly branched, stored in liver & muscles.
**B. Cellulose: structural.
**C. Starch: plant storage.
**D. Chitin: structural in fungi.

Q87.

Which linkage occurs in cellulose?
A. α-1,4
B. β-1,4 ✅
C. α-1,6
D. β-1,6

Explanation:

A. α-1,4: In amylose.
B. β-1,4 (Correct): Linear glucose polymer in cellulose.
C. α-1,6: Branches in amylopectin/glycogen.
D. β-1,6: Rare, not cellulose.

Q88.

Which polysaccharide is used as an energy reserve in fungi?
A. Glycogen ✅
B. Cellulose
C. Starch
D. Chitin

Explanation:

A. Glycogen (Correct): Storage in fungi and animals.
**B. Cellulose: plant cell wall.
**C. Starch: plants.
**D. Chitin: fungal wall, not energy storage.

Q89.

Which sugar gives blue-black color with iodine?
A. Cellulose
B. Starch ✅
C. Glucose
D. Glycogen

Explanation:

**A. Cellulose: does not.
B. Starch (Correct): Iodine test → blue-black.
**C. Glucose: no such test.
**D. Glycogen: reddish-brown with iodine.

Q90.

Which sugar is a pentose?
A. Glucose
B. Fructose
C. Ribose ✅
D. Maltose

Explanation:

**A. Glucose: hexose.
**B. Fructose: hexose.
C. Ribose (Correct): Five-carbon sugar in RNA.
**D. Maltose: disaccharide.

Q91.

Which is the sweetest natural sugar?
A. Glucose
B. Fructose ✅
C. Sucrose
D. Lactose

Explanation:

**A. Glucose: less sweet.
B. Fructose (Correct): Sweetest natural monosaccharide.
**C. Sucrose: table sugar, less sweet than fructose.
**D. Lactose: least sweet.

Q92.

Which is the repeating unit of chitin?
A. N-acetylglucosamine ✅
B. Galactose
C. Mannose
D. Ribose

Explanation:

A. N-acetylglucosamine (Correct): Linked by β-1,4 bonds in chitin.
**B. Galactose: in lactose.
**C. Mannose: part of glycoproteins.
**D. Ribose: nucleic acid sugar.

Q93.

Which sugar is called “milk sugar”?
A. Sucrose
B. Lactose ✅
C. Maltose
D. Trehalose

Explanation:

**A. Sucrose: cane sugar.
B. Lactose (Correct): Glucose + galactose, present in milk.
**C. Maltose: malt sugar.
**D. Trehalose: fungal sugar.

Q94.

Which polysaccharide is water-soluble?
A. Starch
B. Glycogen ✅
C. Cellulose
D. Chitin

Explanation:

**A. Starch: insoluble in cold water.
B. Glycogen (Correct): Highly branched → more soluble.
**C. Cellulose: insoluble.
**D. Chitin: insoluble.

Q95.

Which test is specific for reducing sugars?
A. Iodine test
B. Benedict’s test ✅
C. Millon’s test
D. Biuret test

Explanation:

**A. Iodine: starch.
B. Benedict’s (Correct): Cu²⁺ reduced to Cu₂O → brick-red ppt.
**C. Millon’s: tyrosine.
**D. Biuret: proteins.

Q96.

Which polysaccharide is unbranched?
A. Amylose ✅
B. Amylopectin
C. Glycogen
D. Cellulose

Explanation:

A. Amylose (Correct): Linear α-1,4 glucose polymer.
**B. Amylopectin: branched.
**C. Glycogen: highly branched.
**D. Cellulose: linear, but not storage carbohydrate.

Q97.

Which carbohydrate functions as an anticoagulant?
A. Glycogen
B. Heparin ✅
C. Starch
D. Cellulose

Explanation:

**A. Glycogen: energy storage.
B. Heparin (Correct): Sulfated polysaccharide with anticoagulant property.
**C. Starch: energy storage.
**D. Cellulose: structural.

Q98.

Which disaccharide is present in barley and malt?
A. Maltose ✅
B. Sucrose
C. Lactose
D. Trehalose

Explanation:

A. Maltose (Correct): “Malt sugar” in germinating barley.
**B. Sucrose: cane sugar.
**C. Lactose: milk sugar.
**D. Trehalose: fungal sugar.

Q99.

Which polysaccharide serves as dietary fiber in humans?
A. Glycogen
B. Starch
C. Cellulose ✅
D. Amylopectin

Explanation:

**A. Glycogen: animal storage, digested.
**B. Starch: digested.
C. Cellulose (Correct): Humans lack cellulase → acts as fiber.
**D. Amylopectin: digestible starch.

Q100.

Which carbohydrate test involves iodine solution?
A. Benedict’s test
B. Iodine test ✅
C. Molisch’s test
D. Fehling’s test

Explanation:

**A. Benedict’s: reducing sugars.
B. Iodine (Correct): Detects starch → blue-black color.
**C. Molisch’s: general carbohydrate test.
**D. Fehling’s: reducing sugars.

Biomolecules Class 11 Biology, CBSE Class 11 Biology MCQs, NCERT Biomolecules chapter notes, Proteins lipids nucleic acids, Enzyme types and properties, NEET UG Biomolecules preparation, Online learning Biology MCQs, Class 11 Biology NEET prep, biomolecules class 11 biology mcqs for neet, enzymes types properties and action mcqs, proteins carbohydrates lipids nucleic acids notes, ncert class 11 biology biomolecules solved questions, online learning biomolecules mcqs for neet ug, cbse class 11 biomolecules chapter mcqs, structure and function of enzymes class 11 mcqs, biomolecules chapter important questions for neet

Part 4 — Carbohydrates: Monosaccharides, Disaccharides, Polysaccharides, Tests & Functions (Q76–100)