All Free Biology MCQs with Answers

Every Biology question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.

19,844 questions · page 914 of 993

  • A. Four 6-C rings
  • B. Three 6-C rings and two 5-C rings
  • C. Three 6-C rings and one 5-C ring
  • D. Three 6-C rings only
  • E. Two 6-C rings and one 5-C ring

Explanation: Explanation for this question will be added soon.

Correct answer: Three 6-C rings and one 5-C ring
  • A. A
  • B. B
  • C. K
  • D. D

Explanation: The explanation for this question will be added soon.

Correct answer: K
  • A. Solid
  • B. Liquid
  • C. Gas
  • D. Plasma

Explanation: Option A is correct since animal fats most commonly include, saturated fats that have a high melting point, and are solids at room…

Correct answer: Solid
  • A. Waxes
  • B. Fats
  • C. Both Options A and B are correct
  • D. None of these options are correct

Explanation: Esters of fatty acids with higher alcohols other than glycerol are said to be waxes.

Correct answer: Waxes
  • A. Glycogen
  • B. Starch
  • C. Fat
  • D. Cholesterol

Explanation: Fat, or adipose tissue, is the molecule used by most animals for long-term energy storage.

Correct answer: Fat
  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation: Triglyceride being non-polar do not dissolve in water. They store a lot of energy in them and are hydrolysed to release water.

Correct answer: Option A
  • A. As insulating material
  • B. Providing more energy
  • C. As exoskeleton
  • D. As cuticle of leaves

Explanation: Lipids are an energy-rich macromolecule, and the carbon-hydrogen bonds in lipids store a lot of energy.

Correct answer: Providing more energy
  • A. High proportion of oxygen
  • B. High C-O ratio
  • C. Low proportion of Carbon
  • D. High proportion of C-H

Explanation: The normal oxidative process yields approximately 9 kcal per gram of fats, and approximately 4 kcal per gram for carbohydrates.

Correct answer: High proportion of C-H
  • A. Saponification number
  • B. Saponification
  • C. Both Options A and B are correct
  • D. None of these options are correct

Explanation: Saponification is a process involving the hydrolysis of fats on its reaction with alkali, thereby leading to the formation of salts of…

Correct answer: Saponification
  • A. Waxes
  • B. Fats
  • C. Both A and B
  • D. None of these

Explanation: Fats (acylglycerol) are esters of fatty acids and glycerol.Natural waxes are esters of long-chain fatty acids and long-chain alcohols.

Correct answer: Waxes
  • A. Acetic acid
  • B. Oleic acid
  • C. Palmitic acid
  • D. All of these options are correct

Explanation: Palmitic acid is a saturated fatty acid (thus it has a high melting point) and is also soluble in organic solvents.

Correct answer: Palmitic acid
  • A. Hydrophilic Carbohydrates
  • B. Hydrophobic fats
  • C. Both a and b
  • D. None of these

Explanation: Option A : Carbohydrate groups are present only on the outer surface of the plasma membrane and are attached to proteins, forming…

Correct answer: Both a and b
  • A. Animals
  • B. Plants
  • C. Both
  • D. None of these

Explanation: Carotenoids perform a protective function in plants. They act as pigments and antioxidants, helping to protect plant cells from damage…

Correct answer: Both

18274. Cholesterol is:

  • A. Animal sterol
  • B. C27H46O
  • C. 5 methyl groups
  • D. All of these

Explanation: Cholestrol is an animal sterol which the structure shown below indicating the presence of 5 methyl groups and the molecular formula C27H46O.

Correct answer: All of these
  • A. C26
  • B. C25
  • C. C30
  • D. C28

Explanation: Fatty acids in acylglycerols contain carbon atoms in even numbers. C25 is the only one with an odd number of carbons.

Correct answer: C25
  • A. Lipotropism
  • B. Blood cloting factors
  • C. Used for energy production
  • D. None of these

Explanation: Essential fatty acids are used as blood clotting factors and energy production.

Correct answer: Lipotropism
  • A. C-C
  • B. C-H
  • C. C-N
  • D. C-O

Explanation: C-H bond has a high bond energy so it breaks to give a lot of energy; thus, lipids due to thor long fatty acid chains have higher energy…

Correct answer: C-H
  • A. DNA
  • B. RNA
  • C. ATP
  • D. Triglycerides

Explanation: In triglycerides, 3 fatty acid chains form ester bonds with a glycerol molecule which has 3 alcohol groups.

Correct answer: Triglycerides
  • A. neutral lipid
  • B. natural lipid
  • C. wax
  • D. all of these

Explanation: Neutral lipids are called so because the have no charge as they do not contain acidic or basic groups.

Correct answer: neutral lipid
  • A. Energy source
  • B. Structure of membrane
  • C. Mechanical protection
  • D. All of these options are correct

Explanation: Lipids function as an energy reserve, regulate hormones, membrane lipid layer formation, transmit nerve impulses, cushion vital organs…

Correct answer: All of these options are correct