11. Which of the following is the main constituent of the Gobar gas? (UPSC Prelims 1979).
[A] Carbon dioxide
[B] Methane
[C] Ethylene
[D] Carbon monoxide
Show Answer
Correct Answer: B [Methane]
Notes:
Biogas or Gobar gas is produced by the breakdown of organic matter in the absence of oxygen. It can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste. It is a renewable energy source. It comprises primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes. It is produced by anaerobic digestion.
12. How the body temperature is maintained?
[A] Due to temperature regulating mechanism located in the base of the brain
[B] Due to excessive intake of water
[C] Due to regular intake of foods
[D] Due to the constant flow of blood in the capillaries
Show Answer
Correct Answer: A [Due to temperature regulating mechanism located in the base of the brain]
Notes:
The hypothalamus part of the brain works with other parts of the body’s temperature-regulating system, such as the skin, sweat glands and blood vessels. Water evaporating from the skin cools the body, keeping its temperature in a healthy range.
13. Which one of the following types of micro-organisms is most widely used in industries? (UPSC Prelims 1998)
[A] Bacteria
[B] Bacteria and fungi
[C] Bacteria and algae
[D] Bacteria, micro-algae and fungi
Show Answer
Correct Answer: D [Bacteria, micro-algae and fungi]
Notes:
Bacteria, micro-algae and fungi are most widely used in industries
14. Which vitamin is also called as “Pantothenic acid”?
[A] Vitamin K
[B] Vitamin D
[C] Vitamin B3
[D] Vitamin B5
Show Answer
Correct Answer: D [Vitamin B5]
Notes:
Vitamin B5 is also called as Pantothenic acid and it was discovered by Roger J.Williams in 1933. Chemical formula for Vitamin B5 is C9H17NO5.
15. Which among the following vitamins is absent in an egg?
[A] Vitamin D
[B] Vitamin C
[C] Vitamin A
[D] Vitamin K
Show Answer
Correct Answer: B [Vitamin C]
Notes:
Egg is devoid of vitamin C. Egg contains all the vitamins barring vitamin C.
Extra info: Egg yolk is one of the few foods which contains vitamin D.
16. Which device is used to measure the growth in plants?
[A] Anemograph
[B] Seismograph
[C] Crescograph
[D] All the above
Show Answer
Correct Answer: C [Crescograph]
Notes:
Crescograph is a device which is used to measure the growth in plants which was developed by Sir Jagadish Chandra Bose in the first half of 20th century.
17. Gonyaulax, which are known for causing red tides, belong to which of the following?
[A] Algae
[B] Fungi
[C] Protista
[D] Bacteria
Show Answer
Correct Answer: C [Protista ]
Notes:
Red tides are caused by Gonyaulax which are small, microscopic organisms that grow in water and also called dinoflagellates.
18. The study of cell biology is related to which of the following?
[A] the cell is the fundamental unit of life
[B] cell structure and function
[C] Both 1 & 2
[D] None of these
Show Answer
Correct Answer: C [Both 1 & 2 ]
Notes:
Cell biology is the study of cell structure and function. It revolves around the concept that the cell is the fundamental unit of life.
19. Why lysosomes are called suicidal bags?
[A] because it contains digestive enzymes
[B] because it contains endoplasmic reticulum
[C] because it contains Phospholipids
[D] None of these
Show Answer
Correct Answer: A [because it contains digestive enzymes]
Notes:
The lysosome is known as the suicide bag of the cell because it contains digestive enzymes.
20. A segment of DNA consists of 120 adenine and 120 cytosine bases. What is the total number of nucleotides present in the segment?
[A] 120
[B] 240
[C] 345
[D] 480
Show Answer
Correct Answer: D [480]
Notes:
According to Chargaff’s laws, the amount of adenine is always equal to that of thymine, and the amount of guanine is always equal to that of cytosine, i.e. A = T(120) and G = C (120), hence, the total no. The number of nucleotides would be 120 x 4 = 480.
