Chemical Building Blocks of Life UPSC Questions

Chemical Building Blocks of Life MCQ Questions

1.
Why should a magnesium ribbon be cleaned before burning in air?
A.
To remove moisture
B.
To remove dirt
C.
To remove oxide layer
D.
To increase brightness
ANSWER :
C. To remove oxide layer
2.
Which of the following is a balanced chemical equation?
A.
Mg + Oโ‚‚ โ†’ MgO
B.
Zn + Hโ‚‚SOโ‚„ โ†’ ZnSOโ‚„ + Hโ‚‚
C.
Fe + Hโ‚‚O โ†’ Feโ‚ƒOโ‚„ + Hโ‚‚
D.
Zn + Oโ‚‚ โ†’ ZnO
ANSWER :
B. Zn + Hโ‚‚SOโ‚„ โ†’ ZnSOโ‚„ + Hโ‚‚
3.
What kind of reaction is CaO + Hโ‚‚O โ†’ Ca(OH)โ‚‚?
A.
Decomposition
B.
Combination
C.
Displacement
D.
Double displacement
ANSWER :
B. Combination
4.
In which reaction is heat absorbed?
A.
Respiration
B.
Burning of coal
C.
Photosynthesis
D.
Cooking of food
ANSWER :
C. Photosynthesis
5.
Which of the following is a decomposition reaction?
A.
Hโ‚‚ + Clโ‚‚ โ†’ 2HCl
B.
2AgCl โ†’ 2Ag + Clโ‚‚
C.
2KBr + Clโ‚‚ โ†’ 2KCl + Brโ‚‚
D.
Mg + Oโ‚‚ โ†’ MgO
ANSWER :
B. 2AgCl โ†’ 2Ag + Clโ‚‚
6.
Microsatellite DNAโ€™ is used in the case of which one of the following?

UPSC - 2023

A.
Studying the evolutionary relationships among various species of fauna
B.
Stimulating โ€˜stem cellsโ€™ to transform into diverse functional tissues
C.
Promoting clonal propagation of horticultural plants
D.
Assessing the efficacy of drugs by conducting series of drug trials in a population
ANSWER :
A. Studying the evolutionary relationships among various species of fauna