Biology (CDS-Solved Paper)

Total Questions: 50

41. Which one of the following elements is involved in the control of water content of the blood? [Morning Shift-2018 (I)]

Correct Answer: (a) Potassium
Solution:

Potassium ions are the most abundant cations within tissue fluids. These activate many enzymes, participate in the oxidation of glucose to produce ATP. In blood plasma, potassium level is only 5 mmolL⁻¹ within the red blood cells. These concentrations change to 105 m mol (K⁺).

42. Which one of the following gases dissolves in water to give acidic solution? [Morning Shift-2018 (I)]

Correct Answer: (a) Carbon dioxide
Solution:

Carbon dioxide dissolve in water to form acidic solution. Aqueous solution of carbon dioxide forms carbonic acid (H₂CO₃).

43. Which one of the following elements is essential for the formation of chlorophyll in green plants? [Morning Shift-2018 (I)]

Correct Answer: (c) Magnesium
Solution:

Magnesium element is essential for the formation of chlorophyll in green plants. It is the main pigment for the absorption of light in plants is chlorophyll which contains magnesium ion.

44. Which one of the following proteins gives lustrous shiny appearance to silk fibre? [Evening Shift-2017 (II)]

Correct Answer: (a) Fibrin
Solution:

Fibrin protein constitute 80% of the silk fibre which gives it lustrous shiny appearance. It is produced by cocoon of silkworm.

45. Blue baby syndrome is caused by the contamination of [Evening Shift-2017 (II)]

Correct Answer: (a)
Solution:

Nitrite gets accumulated in water bodies due to excessive use of nitrogen fertiliser. It causes blue baby syndrome. It hiders with transport of O₂.

46. Match List I with List II and select the correct answer using the code given below. [Evening Shift-2017 (II)]

Correct Answer: (c)
Solution:

The most prominent roles of mitochondria are to produce the energy currency of the cell, i.e. ATP. The main role of chloroplasts is to conduct photosynthesis. Ribosomes are a cell organelles that makes protein. Inside a cell, numerous organelles function to remove wastes. One of the key organelles involved in digestion and waste removal is the lysosome.

47. Human insulin molecule is composed of one α-chain having 21 amino acids and one β-chain having 30 amino acids. How many functional insulin genes occur in adult humans? [Evening Shift-2017 (II)]

Correct Answer: (b) Two
Solution:

One gene makes one polypeptide, so two chain of insulin protein will be synthesised by two genes.

48. A biological community in its environment such as a pond, an ocean, a forest, even an aquarium is known as [Evening Shift-2017 (II)]

Correct Answer: (a) biome
Solution:

A biological community in its environment such as a pond, an ocean, a forest, even an aquarium all together form a biome.

49. The foul smell of urine of a healthy man having healthy food, when spilled on floor, is mainly due to the bacterial decomposition of [Evening Shift-2017 (II)]

Correct Answer: (d) urea into ammonia
Solution:

Urea is degraded by bacteria into ammonia, so it causes foul smell when accumulated at one place.

50. Desalination of sea water is done by using reverse osmosis. The pressure applied to the solution is [Evening Shift-2017 (II)]

Correct Answer: (a) larger than osmotic pressure
Solution:

When a pressure, more than the osmotic pressure is applied to the solution, the solvent may pass from solution into the solvent through the semi-permeable membrane. This type of osmosis is known as reverse osmosis. Reverse osmosis is used for the desalination of sea water.