All Free Biology MCQs with Answers

4381. In free state, glucose is present in:

• A. Grapes
• B. Figs
• C. Dates
• D. All fruits

Explanation: It is found in all fruits however it is abundant in grapes, dates and figs.

4382. In combined form glucose is found in:

• A. Many disaccharides & polysaccharides
• B. All oligosaccharides & polysaccharides
• C. All disaccharides & polysaccharides
• D. All trisaccharides & polysaccharides

Explanation: Glucose is part of sucrose, maltose and fructose which are disaccharides. Similarly, cellulose starch and glycogen are polymers of glucose. However, some disaccharides and polysaccharides may have a monomer other than glucose.

4383. Starch, cellulose and glycogen yield _ on complete hydrolysis:

• A. Fructose
• B. Mannose
• C. Glucose
• D. Galactose

Explanation: Starch glycogen and cellulose are polymers of glucose monomers and they are synthesized by condensation of glucose monomers. Thus yield glucose monomers upon hydrolysis.

4384. The chemical energy stored in 10 grams of glucose is:

• A. 7170.6 Kcal
• B. 7170.6 cal
• C. 717.6 Kcal
• D. 720.6 Kcal

Explanation: As per PTB, energy stored in 10g of glucose is 717.6 kcal.

4385. These are comparatively less sweet in taste and less soluble in water:

• A. Monosaccharides
• B. Oligosaccharides
• C. Disaccharides
• D. Polysaccharides

Explanation: These are intermediate or moderate carbohydrates having properties in between monosaccharides and polysaccharides. However, disaccharides are soluble like monosaccharides.

4386. Carbon number _ of glucose and _ of fructose respectively make a glycosidic bond to give rise to a sucrose.

• A. 4, 4
• B. 1, 2
• C. 1, 4
• D. 2, 1

Explanation: It is condensation product of D-glycopyranose and L-fructofuranose. Thus carbon no.1 of glucose and carbon no.2 of fructose are involved. See the figure given in explanation of Q # 36.

4387. The most complex and the most abundant carbohydrates in nature are:

• A. Monosaccharides
• B. Oligosaccharides
• C. Disaccharides
• D. Polysaccharides

Explanation: Polysaccharides: Polysaccharides are the most complex and abundant carbohydrates in nature. They consist of long chains of monosaccharide units linked together. Examples of polysaccharides include starch, cellulose, and glycogen. Polysaccharides have various functions, including energy storage, structural support, and cell signaling. They can be found in plants, animals, and microorganisms.

4388. The carbohydrates which are only sparingly soluble in water are:

• A. Monosaccharides
• B. Disaccharides
• C. Oligosaccharides
• D. Polysaccharides

Explanation: Correct answer: D) Polysaccharides are the carbohydrates that are only sparingly soluble in water.

4389. It consists of an unbranched chain of α glucose monomers:

• A. Amylopectin
• B. Glycogen
• C. Cellulose
• D. Amylose

Explanation: Correct option: D) Amylose consists of an unbranched chain of α-glucose monomers.

4390. Amylopectin starches have _ chains and are _ in hot or cold water.

• A. Unbranched, soluble
• B. Unbranched, insoluble
• C. Branched, soluble
• D. Branched, insoluble

Explanation: Correct option: D) Amylopectin starches have branched chains and are insoluble in hot or cold water.