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 among the following minerals is also known as Horn Silver?
[A] Silver Iodide
[B] Silver Chroride
[C] Zinc Phosphate
[D] Silver Sulphide
Show Answer
Correct Answer: B [Silver Chroride]
Notes:
Chlorargyrite is the mineral form of silver chloride (AgCl). It is also known as cerargyrite and, when weathered by desert air, as horn silver. Silver chloride is formed by the disappearance of the initial silver oxide layer.
2. How the Cast Iron is different from Wrought Iron?
- Cast iron have higher carbon content than wrought iron
- Cast iron are more ductile compared to wrought iron
- Wrought iron is more stable, pure and stronger, compared to cast iron
Select the correct option from the codes given below:
[A] 3 Only
[B] 1 and 3 Only
[C] 2 and 3 Only
[D] 1,2 and 3
Show Answer
Correct Answer: B [ 1 and 3 Only]
Notes:
Second statement is wrong because wrought iron is more ductile compared to cast iron
3. Which of the following makes the skin layer impervious to water?
[A] Melanin
[B] Collagen
[C] Keratin
[D] Chitin
Show Answer
Correct Answer: C [Keratin]
Notes:
Keratin is a family of fibrous structural proteins involved in making up the outer layer of human skin. It is also the key structural component of hair and nails. Cells in the epidermis contain a structural matrix of keratin, which makes this outermost layer of the skin almost waterproof, and along with collagen and elastin, gives skin its strength. It also makes up fish scales and crustacean shells, bird feathers and beaks, animal horns and hooves.
4. If waste materials contaminate the source of drinking water, which of the following diseases will spread?
[A] Typhoid
[B] Malaria
[C] Anaemia
[D] Scurvy
Show Answer
Correct Answer: A [Typhoid]
Notes:
Typhoid is a common worldwide bacterial disease transmitted by the ingestion of food or water contaminated with the feces of an infected person, which contain the bacterium Salmonella enterica subsp. enterica, serovar Typhi.
5. Flowers emit fragrance to ____:
[A] Drive away flies
[B] Purify air
[C] Attract insects
[D] All of the above
Show Answer
Correct Answer: C [Attract insects]
Notes:
Flowers emit fragrance to attract pollinators which are mainly insects. The fragrance plays a prominent role in the localization and selection of flowers by insects, especially moth-pollinated flowers, which are detected and visited at night. If they have become infested with herbivores like caterpillars, they attract beneficial insects like parasitic wasps with the help of scent signals from their leaves.
6. 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.
7. The biological process in which both aerobes and anaerobes degrade organic matter is ____:
[A] Digesting
[B] Composting
[C] Manuring
[D] Nutrifying
Show Answer
Correct Answer: B [Composting]
Notes:
Composting is the depomposition of plant remains and other once-living materials to make an earthy, dark, crumbly substance that is excellent for enriching soil. It is the chief way to recycle wastes.
8. 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.
9. Blue-green algae are included in the group ____:
[A] Protozoa
[B] Eubacteria
[C] Fungi
[D] Cyanobacteria
Show Answer
Correct Answer: D [Cyanobacteria]
Notes:
Cyanobacteria, also known as blue green algae, are single-celled and belong to the family of Prokaryotes. That means, they do not have a well defined cell nucleus. The ability of cyanobacteria to perform oxygenic photosynthesis is thought to have converted the early reducing atmosphere into an oxidizing one, which dramatically changed the composition of life forms on Earth by stimulating biodiversity and leading to the near-extinction of oxygen-intolerant organisms.
10. What is the Normal Blood Volume in human adult?
[A] 1 litre
[B] 3 litre
[C] 5 litre
[D] 7 litre
Show Answer
Correct Answer: C [5 litre]
Notes:
The average adult has a blood volume of roughly 4-5 to 5 litres, which is composed of plasma and several kinds of cells. By volume, the red blood cells constitute about 45% of whole blood, the plasma about 54.3%, and white cells about 0.7%.
