Here below some basic MCQ’s about “Carbohydrates, proteins, vitamins and nucleic acid” with answer which is explained in details for exam practice. Let’s check one by one.
Q1. Which of the following is a reducing sugar?
(a) Sucrose
(b) Lactose
(c) Starch
(d) Cellulose
Answer: (b) Lactose
Explanation: Reducing sugars are sugars that can donate electrons to other molecules, typically through their free aldehyde or ketone groups. Lactose is a reducing sugar because it has a free anomeric carbon that can reduce other substances. Sucrose is non-reducing because its glycosidic bond involves both anomeric carbons, and starch and cellulose are polysaccharides that do not show reducing properties.
Q2. The basic unit of cellulose is:
(a) Glucose
(b) Fructose
(c) Ribose
(d) Galactose
Answer: (a) Glucose
Explanation: Cellulose is a polysaccharide made of β-D-glucose units. These glucose units are linked by β-1,4-glycosidic bonds, forming long, straight chains, which gives cellulose its structural strength in plants.
Q3. Which of the following is not a function of proteins?
(a) Enzymatic activity
(b) Genetic information storage
(c) Transport of molecules
(d) Structural support
Answer: (b) Genetic information storage
Explanation: Proteins perform many functions in the body, including enzymatic activity (as enzymes), transport of molecules (as in hemoglobin), and providing structural support (as in collagen). However, the storage of genetic information is the function of nucleic acids like DNA, not proteins.
Q4. Which of the following is an essential amino acid?
(a) Glycine
(b) Alanine
(c) Lysine
(d) Proline
Answer: (c) Lysine
Explanation: Essential amino acids are those that cannot be synthesized by the human body and must be obtained from the diet. Lysine is one of these essential amino acids. Glycine, alanine, and proline can be synthesized by the body.
Q5. Deficiency of which vitamin causes night blindness?
(a) Vitamin A
(b) Vitamin D
(c) Vitamin K
(d) Vitamin E
Answer: (a) Vitamin A
Explanation: Vitamin A is crucial for the maintenance of healthy vision. A deficiency in vitamin A impairs the production of rhodopsin, a pigment in the retina, leading to night blindness.
Q6. Vitamin K is essential for:
(a) Vision
(b) Blood clotting
(c) Bone formation
(d) Nerve function
Answer: (b) Blood clotting
Explanation: Vitamin K is necessary for the synthesis of clotting factors in the liver. A deficiency in vitamin K can lead to excessive bleeding due to impaired blood clotting.
Nucleic Acids MCQs
Q7. The bond between two nucleotides in a DNA strand is:
(a) Hydrogen bond
(b) Phosphodiester bond
(c) Glycosidic bond
(d) Ionic bond
Answer: (b) Phosphodiester bond
Explanation: Nucleotides in a DNA strand are connected by phosphodiester bonds, which form between the phosphate group of one nucleotide and the hydroxyl group of another. These bonds create the sugar-phosphate backbone of the DNA strand.
Q8. Which of the following is not a component of RNA?
(a) Adenine
(b) Thymine
(c) Uracil
(d) Guanine
Answer: (b) Thymine
Explanation: RNA contains the nitrogenous bases adenine, uracil, cytosine, and guanine. Thymine is present only in DNA, where it pairs with adenine, whereas uracil replaces thymine in RNA.
Q9. Which form of RNA carries the genetic code from the nucleus to the ribosome for protein synthesis?
(a) tRNA
(b) mRNA
(c) rRNA
(d) snRNA
Answer: (b) mRNA
Explanation: Messenger RNA (mRNA) carries the genetic instructions from DNA in the nucleus to the ribosomes in the cytoplasm, where proteins are synthesized based on the mRNA sequence.
Q10. Glycogen is primarily stored in which of the following tissues?
(a) Liver and skeletal muscles
(b) Adipose tissue
(c) Pancreas
(d) Kidneys
Answer: (a) Liver and skeletal muscles
Explanation: Glycogen is the storage form of glucose in animals. It is primarily stored in the liver, where it helps regulate blood glucose levels, and in skeletal muscles, where it serves as an energy reserve for muscle contraction.
Leave a comment