All Free Biology MCQs with Answers

4281. _ are the major site for storage of glycogen in animal's body.

• A. Muscle and Liver
• B. Around Thighs and Belly
• C. Around Belly and Hips
• D. Liver and Kidneys

Explanation: Glycogen is called animal starch and it is abundantly found in muscle and liver cells of animal tissue.

4282. The number of amino acids that have been found to occur in cells and tissues are:

• A. 170
• B. 20
• C. 25
• D. 45

Explanation: About 170 types of amino acids have been found to occur in cells and tissues. Of these, about 25 are constituents of proteins. Most of the proteins are however, made of 20 types of amino acids.

4283. Most proteins are made up of _ type of amino acid.

• A. 20
• B. 170
• C. 25
• D. 200

Explanation: There are 20 standard amino acids that are commonly found in cells and tissues. These are the building blocks of proteins and play essential roles in various biological processes. The 20 standard amino acids are:

4284. If in lipids there is a higher proportion of unsaturated fatty acid then it will be:

• A. Oils
• B. Waxes
• C. Phenols
• D. Fats

Explanation: Fats containing unsaturated fatty acids are usually liquid at room temperature and are said to be oils. Fats containing saturated fatty acids are solids.

4285. When X-rays are passed through crystalline DNA, it shows helix making one twist every:

• A. 2nm
• B. 3.4nm
• C. 34nm
• D. 4nm

Explanation: The two strands of DNA are wound around each other so that there are 10 base pairs in each turn of about 3.4nm.

4286. Which of the following type of carbohydrate has high molecular weight and is sparingly soluble in water?

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

Explanation: Polysaccharides are made up of many monosaccharides subunits and have higher molecular weight as compared to monosaccharides and oligosaccharides. Polysaccharides are sparingly soluble in water while monosaccharides has high solubility.

4287. Which of the following holds the alpha helix of protein in its place?

• A. Hydrogen bond
• B. Amino group
• C. R-group
• D. Disulphide bond

Explanation: The a-helix is a very uniform geometric structure with 3.6 amino acids in each turn of the helix. The helical structure is kept by the formation of hydrogen bonds among the amino acids molecules in successive turns of the spiral.

4288. The number and sequence of amino acids along a polypeptide chain is called _ structure of a protein.

• A. Secondary
• B. Quaternary
• C. Primary
• D. Tertiary

Explanation: The primary structure of a protein is described by number, sequence and type of amino acids in a polypeptide chains.

4289. If water has high latent heat of vaporization, how this property of water could be helpful to plants and animals?

• A. With the release of large amount of water vapors, a small amount of heat loss can take place
• B. No cooling effect with the release of even large amount of water vapors
• C. It will keep their temperature very high
• D. With the release of small amount of water vapors, a great amount of heat loss can take place

Explanation: Water absorbs much heat as it changes from liquid to gas and causes a cooling effect. Evaporation of only two ml out of one liter of water lowers the temperature of the remaining 998 ml by 1 °C.

4290. Starch is present in tuber, fruits and grains but absent in animal cells. Instead animals have a substance stored in liver and muscles known as:

• A. Glucose
• B. Glycogen
• C. Galactose
• D. Glucagon

Explanation: Glycogen is animal starch found in liver and muscle cell while starch is stored in plants cells.