Q.1 Which of the following is a monosaccharide?
Sucrose
Maltose
Glucose
Lactose
Explanation - Glucose is a simple sugar (monosaccharide) whereas sucrose, maltose, and lactose are disaccharides.
Correct answer is: Glucose
Q.2 Which bond links amino acids in a protein?
Glycosidic bond
Peptide bond
Ester bond
Hydrogen bond
Explanation - A peptide bond forms between the amino group of one amino acid and the carboxyl group of another.
Correct answer is: Peptide bond
Q.3 Which of the following is a structural polysaccharide in plants?
Starch
Cellulose
Glycogen
Chitin
Explanation - Cellulose provides structural support in plant cell walls, whereas starch and glycogen are storage polysaccharides.
Correct answer is: Cellulose
Q.4 Lipids are primarily composed of:
C, H, O
C, H, N
C, H, O, N
C, H, O, P
Explanation - Lipids are mainly composed of carbon, hydrogen, and oxygen, with very little oxygen compared to carbohydrates.
Correct answer is: C, H, O
Q.5 Which vitamin is fat-soluble?
Vitamin B12
Vitamin C
Vitamin D
Vitamin B6
Explanation - Vitamins A, D, E, and K are fat-soluble, whereas most B-complex vitamins and vitamin C are water-soluble.
Correct answer is: Vitamin D
Q.6 Which of the following nucleotides is a purine?
Adenine
Thymine
Cytosine
Uracil
Explanation - Purines include adenine and guanine, while thymine, cytosine, and uracil are pyrimidines.
Correct answer is: Adenine
Q.7 Which polysaccharide is used by animals for energy storage?
Cellulose
Starch
Glycogen
Chitin
Explanation - Glycogen is the main storage polysaccharide in animals, stored primarily in liver and muscle cells.
Correct answer is: Glycogen
Q.8 Which of the following is an essential amino acid?
Glycine
Alanine
Leucine
Serine
Explanation - Leucine cannot be synthesized by the human body and must be obtained from the diet.
Correct answer is: Leucine
Q.9 Which of the following is a disaccharide?
Fructose
Glucose
Sucrose
Galactose
Explanation - Sucrose is made of glucose and fructose; glucose and fructose are monosaccharides.
Correct answer is: Sucrose
Q.10 Which functional group is present in all amino acids?
Hydroxyl group
Carboxyl group
Carbonyl group
Sulfhydryl group
Explanation - Amino acids contain both an amino group (-NH2) and a carboxyl group (-COOH) as their functional groups.
Correct answer is: Carboxyl group
Q.11 Which enzyme breaks down starch into maltose?
Lipase
Amylase
Protease
Lactase
Explanation - Amylase catalyzes the hydrolysis of starch into maltose during digestion.
Correct answer is: Amylase
Q.12 Which type of lipid forms biological membranes?
Triglycerides
Phospholipids
Steroids
Waxes
Explanation - Phospholipids are major components of cell membranes, with hydrophilic heads and hydrophobic tails forming bilayers.
Correct answer is: Phospholipids
Q.13 Which molecule is the primary energy currency of the cell?
DNA
ATP
RNA
Glucose
Explanation - Adenosine triphosphate (ATP) stores and provides energy for cellular processes.
Correct answer is: ATP
Q.14 Which vitamin is water-soluble?
Vitamin A
Vitamin D
Vitamin E
Vitamin C
Explanation - Vitamin C is water-soluble, meaning it dissolves in water and is not stored extensively in the body.
Correct answer is: Vitamin C
Q.15 Which of the following is NOT a lipid?
Cholesterol
Phospholipid
Fructose
Triglyceride
Explanation - Fructose is a carbohydrate (monosaccharide), not a lipid.
Correct answer is: Fructose
Q.16 Which nitrogenous base pairs with guanine in DNA?
Adenine
Thymine
Cytosine
Uracil
Explanation - In DNA, guanine pairs with cytosine through three hydrogen bonds.
Correct answer is: Cytosine
Q.17 Which sugar is found in RNA?
Deoxyribose
Ribose
Glucose
Fructose
Explanation - RNA contains ribose sugar, while DNA contains deoxyribose.
Correct answer is: Ribose
Q.18 Which molecule is a polymer of amino acids?
Nucleic acid
Protein
Polysaccharide
Lipid
Explanation - Proteins are polymers made up of amino acid monomers linked by peptide bonds.
Correct answer is: Protein
Q.19 Which of the following is a saturated fatty acid?
Oleic acid
Stearic acid
Linoleic acid
Arachidonic acid
Explanation - Saturated fatty acids have no double bonds between carbon atoms; stearic acid is fully saturated.
Correct answer is: Stearic acid
Q.20 Which biomolecule is most abundant in the human body?
Protein
Carbohydrate
Lipid
Nucleic acid
Explanation - Proteins make up about 50% of the dry mass of most cells and perform diverse functions.
Correct answer is: Protein
Q.21 Which type of RNA carries amino acids to ribosomes?
mRNA
tRNA
rRNA
snRNA
Explanation - Transfer RNA (tRNA) transports specific amino acids to the ribosome for protein synthesis.
Correct answer is: tRNA
Q.22 Which of the following is an example of a steroid?
Cholesterol
Triglyceride
Phospholipid
Glycogen
Explanation - Steroids have a characteristic four-ring structure; cholesterol is a common steroid in animals.
Correct answer is: Cholesterol
Q.23 Which functional group is present in all carbohydrates?
Amino group
Hydroxyl group
Carboxyl group
Sulfhydryl group
Explanation - Carbohydrates contain multiple hydroxyl (-OH) groups attached to carbon atoms.
Correct answer is: Hydroxyl group
Q.24 Which type of bond stabilizes the secondary structure of proteins?
Peptide bond
Disulfide bond
Hydrogen bond
Ionic bond
Explanation - Hydrogen bonds form between backbone atoms, stabilizing alpha-helices and beta-sheets.
Correct answer is: Hydrogen bond
Q.25 Which polysaccharide is found in the exoskeleton of arthropods?
Cellulose
Chitin
Glycogen
Starch
Explanation - Chitin is a nitrogen-containing polysaccharide that provides structural support in arthropod exoskeletons.
Correct answer is: Chitin