General Science Questions (MCQs) for Competitive Examinations
General Science Multiple choice questions for GK paper in SSC, NDA, CDS, UPSC, UPPSC and State PSC Examinations. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
1. Which of the following are used as chemical agents in war?
- Mustard Gas
- Phosgene
- Sarin
- VX
Select the correct option from codes given below:
[A] 1 & 3 Only
[B] 1, 3 & 4 Only
[C] 2 & 4 Only
[D] 1, 2, 3 & 4
Show Answer
Correct Answer: D [ 1, 2, 3 & 4]
Notes:
Chemical weapons are called “poorman’s bomb”. These cause catastrophic damage, and are easy to produce. Sarin is a colorless and odourless agent, and is extremely potent. It was used in Damascus in 2013. Mustard Gas is possibly the most commonly used chemical agent and gets its name from the distinctive odour of rotten mustard. It is less potent and usually only 5 to 10 percent people exposed to it usually die. It was widely used during Second World War. VX is a nerve agent which is odourless and appears as brownish oily substance.
2. Epidermal cells of which part of plant often secrete a waxy water resistant layer on their outer surface?
[A] Aerial parts only
[B] Roots only
[C] Both aerial parts and roots
[D] Neither aerial parts nor roots
Show Answer
Correct Answer: A [Aerial parts only]
Notes:
The major role of epidermis is to protect all the parts of the plant. Epidermal cells on the aerial parts of the plant often secrete a waxy, water-resistant layer on their outer surface. This aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.
3. Which gas is major contributor to greenhouse effect?
[A] Chloroflurocarbon
[B] Nitrogen dioxide
[C] Sulphur dioxide
[D] Carbon dioxide
Show Answer
Correct Answer: D [Carbon dioxide]
Notes:
Greenhouse gases that occur both naturally and from human activities include water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and ozone (O3). These gases contribute to atmospheric warming when they absorb infrared radiation emitted by the solar-warmed Earth and transfer their extra energy to the surrounding atmospheric gases.
4. What is commonly known as white plague?
[A] Typhoid
[B] Malaria
[C] Tuberculosis
[D] Plague
Show Answer
Correct Answer: C [Tuberculosis]
Notes:
Tuberculosis caused by Mycobacterium tuberculie which primarily affects lungs although can affect other body too while early 19th century was called ‘white plague’ because of the large number of the people dying of its infection.
5. Consider the following statements about how plants absorb nitrogen:
- Plants absorb nitrogen in the form of inorganic nitrates or nitrites.
- Plants take in nitrogen in the form of organic compounds.
- Nitrogen is directly taken up by the plants from the atmosphere.
Which of the above statements is / are correct?
[A] Only 1 and 2
[B] Only 1 and 3
[C] Only 2 and 3
[D] All of these
Show Answer
Correct Answer: A [Only 1 and 2]
Notes:
Plants obtain nitrogen through their roots. In the soil, nitrifying bacteria change ammonia into nitrite (NO2 –) and then into nitrate (NO3 –), this process is known as nitrification. Furthermore, plants also absorb nitrogen in an organic form. Several organic compounds (compounds containing carbon) constitute the organic fraction of nitrogen in the soil. The organic matter in the soil exists as decomposing plant and animal residues, relatively stable decomposition-resistant compounds, and humus. The abundance of various forms of nitrogen can be altered by plant roots through the change in pH and secretion of organic compounds or oxygen.
6. The release of which of the following into ponds and wells helps in controlling mosquitoes?
[A] Snail
[B] Crab
[C] Dogfish
[D] Gambusia fish
Show Answer
Correct Answer: D [Gambusia fish]
Notes:
The Gambusia fish, also known as larvivorous stagnant water fish. It feeds on the larvae of mosquitoes. So it helps in controlling their population. It is also called ‘mosquito fish’ and is being used as a biological control measure. Hence, a check on malaria and other vector borne diseases like even dengue.
7. Which of the following micro-organism causes diseases like polio and chicken pox?
[A] Protozoa
[B] Bacteria
[C] Virus
[D] Algae
Show Answer
Correct Answer: C [Virus]
Notes:
Both polio and chicken pox are caused by virus. Poliomyelitis, often called polio or infantile paralysis, is an infectious disease caused by the poliovirus; while, Chickenpox, also known as varicella, is a highly contagious disease caused by the initial infection with varicella zoster virus (VZV).
8. The pigment that gives human skin, hair and eyes their colour is called ____:
[A] Quinacridone
[B] Alizarin
[C] Melanin
[D] Phthalocyanine
Show Answer
Correct Answer: C [Melanin ]
Notes:
The pigment that gives human skin, hair, and eyes their color. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes. Everyone has the same number of melanocytes, but some people make more melanin than others.
9. How the rate of absorption of water through roots can be increased?
[A] Keeping the plants under the fan
[B] Keeping the plants in the dim light
[C] Keeping the plants in the shade
[D] Covering the plants with a polythene bag
Show Answer
Correct Answer: A [Keeping the plants under the fan]
Notes:
When a plant is placed under the fan, the speed of air is increased which leads to high rate of transpiration through the stomata. The increase in the rate of transpiration increases the water absorption also. As by keeping the plants under the fan, the transpiration process is boosted. Therefore, more amount of water and other minerals are absorbed by the plant roots from the soil.
10. Vermicomposting is done by ____:
[A] Bacteria
[B] Worms
[C] Fungus
[D] Animals
Show Answer
Correct Answer: B [Worms]
Notes:
Vermicomposting is the process of using worms also called red worms and micro-organisms to turn kitchen waste into black, earthy-smelling, nutrient-rich humus. Vermicompost is an excellent, nutrient-rich organic fertilizer and soil conditioner.