MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 1489 Mcqs, each offering curated multiple-choice questions to sharpen your 8th Class knowledge and support exam preparation. Choose a topic below to get started.
| 301. |
In which part of atmosphere is ozone layer present? |
| A. | Stratosphere |
| B. | Troposphere |
| C. | Mesosphere |
| D. | Thermosphere |
| Answer» B. Troposphere | |
| 302. |
Which one of the following damages is caused by acid rain? |
| A. | Acid rain destroys forests. |
| B. | Acid rain kills aquatic animals. |
| C. | Acid rain damages historical monuments. |
| D. | All the above |
| E. | None of these |
| Answer» E. None of these | |
| 303. |
What is the main cause of pollution of water in India? |
| A. | Discharge of untreated sewage |
| B. | Bathing |
| C. | Discharge of industrial waste |
| D. | Both (A) and (C) |
| Answer» E. | |
| 304. |
Which one of the following is not a consequence of global warming? |
| A. | Rising sea level. |
| B. | Increased agricultural productivity worldwide. |
| C. | Worsening health effects. |
| D. | Increased storm frequency and intensity. |
| E. | None of these |
| Answer» C. Worsening health effects. | |
| 305. |
Which of the following pollutants is NOT present in the vehicular exhaust emissions? |
| A. | Lead |
| B. | Ammonia |
| C. | Carbon monoxide |
| D. | Particulate matter |
| Answer» C. Carbon monoxide | |
| 306. |
Conservation of water cannot be done by: |
| A. | Cutting vegetation |
| B. | Water recycling |
| C. | Rain water harvesting |
| D. | All the above |
| E. | None of these |
| Answer» B. Water recycling | |
| 307. |
Substances that decay naturally are called: |
| A. | Decomposers |
| B. | Biodegradable |
| C. | Potable |
| D. | Recyclable |
| E. | None of these |
| Answer» C. Potable | |
| 308. |
Trees are planted along the roadside to reduce pollution from motor vehicles. How do trees help to reduce pollution? (i) They absorb traffic noise. (ii) They take in carbon dioxide. (iii) They trap dust and soot from the exhaust pipes of vehicles. |
| A. | (i) and (ii) only |
| B. | (ii) and (iii) only |
| C. | (i) and (iii) only |
| D. | (i), (ii) and (iii) |
| Answer» E. | |
| 309. |
Which of the following air pollutants is wrongly matched with the effect it causes? |
| A. | Dust - reduces photosynthesis in green plants. |
| B. | Carbon monoxide - reduces oxygen in the blood. |
| C. | Chlorofluorocarbons - damages nerves and tissues. |
| D. | Nicotine - hardens and narrows blood vessels. |
| Answer» D. Nicotine - hardens and narrows blood vessels. | |
| 310. |
If there is no\[C{{O}_{2}}\]in the atmosphere, what would happen to the earth's temperature? |
| A. | It would be less than the present. |
| B. | It would be the same as present. |
| C. | It would be higher than the present. |
| D. | It depends on the 0, content of air. |
| Answer» B. It would be the same as present. | |
| 311. |
____ is a measure of the quantity of oxygen used by biological organisms to break down organic material present in a given water sample. |
| A. | Oxygen requirement |
| B. | Potable water |
| C. | Biochemical oxygen demand |
| D. | Physical oxygen demand |
| E. | Non e of these |
| Answer» D. Physical oxygen demand | |
| 312. |
Following are the steps of purification of water. (i) Water collected from the river is made free of large pieces of dirt and pumped into reservoirs. (ii) Water is passed through filter beds. (iii) Water is stirred in a flocculation tank. (iv) Water is allowed to stand in large tanks. (v) Water is chlorinated. (vi) Filtered water is stored. (vii) Water is supplied to homes and factories by huge water mains. Select the option which arrange the steps in correct sequence. |
| A. | (i)\[\to \](iii)\[\to \](iv)\[\to \](ii)\[\to \](v)\[\to \](vi)\[\to \](vii) |
| B. | (i)\[\to \](iv)\[\to \](ii)\[\to \](iii)\[\to \](vi)\[\to \](v)\[\to \](vii) |
| C. | (i)\[\to \](iv)\[\to \](iii)\[\to \](ii)\[\to \](v)\[\to \](vi)\[\to \](vii) |
| D. | (i)\[\to \](ii)\[\to \](iv)\[\to \](v)\[\to \](iii)\[\to \](vi)\[\to \](vii) |
| Answer» B. (i)\[\to \](iv)\[\to \](ii)\[\to \](iii)\[\to \](vi)\[\to \](v)\[\to \](vii) | |
| 313. |
Which of these is the major air pollutant in cities like Delhi and Kolkata? |
| A. | Carbon monoxide |
| B. | Hydrocarbons |
| C. | Suspended particulate matter |
| D. | Oxides of nitrogen |
| Answer» D. Oxides of nitrogen | |
| 314. |
Most part of the ozone layer is found in: |
| A. | Mesosphere |
| B. | Ionosphere |
| C. | Stratosphere |
| D. | Exosphere |
| E. | None of these |
| Answer» D. Exosphere | |
| 315. |
An oil spill covered a large area of water in an ocean. The marine life in that area was badly affected. A lot of marine animals were found dead and floating on the surface of the water. This is because ________. (i) They drank the water that was contaminated by the oil (ii) The fish swallowed the oil and were poisoned (iii) They breathed in the oil fumes near the water surface and were suffocated |
| A. | (ii) only |
| B. | (i) and (ii) only |
| C. | (ii) and (iii) only |
| D. | (i), (ii) and (iii) |
| Answer» E. | |
| 316. |
Which of the major sources of air pollution contributes pollutants like chlorofluorohydrocarbons? |
| A. | Industrial effluents |
| B. | Aerosols |
| C. | Sewage pollutants |
| D. | All of the above |
| Answer» C. Sewage pollutants | |
| 317. |
What is the harmful effect of the depletion of earth's ozone layer? |
| A. | The average temperature of earth's surface will decrease gradually. |
| B. | The oxygen content of the atmosphere will increase. |
| C. | Increased amount of ultra violet radiation will reach earth's surface. |
| D. | Sea levels will go down as the polar ice caps will gradually melt. |
| E. | None of these |
| Answer» D. Sea levels will go down as the polar ice caps will gradually melt. | |
| 318. |
Match column I with column II and select the correct option from the codes given below. Column I Column II (a) Carbon dioxide in air (i) Damage ozone layer (b) Sulphur dioxide in air (ii) Produces acid rain (c) Chlorofluorocarbons (iii) Prevents photosynthesis (d) Dust in air (iv) leads to gloabal warming |
| A. | (a) - (iv); (b) - (ii); (c) - (i); d - (iii) |
| B. | (a) - (iii); (b) - (iv); (c) - (ii); d - (i) |
| C. | (a) - (i); (b) - (ii); (c) - (iv); d - (iii) |
| D. | (a) - (i); (b) - (iii); (c) - (iv); d - (ii) |
| Answer» B. (a) - (iii); (b) - (iv); (c) - (ii); d - (i) | |
| 319. |
How are monuments of marble destroyed? |
| A. | By sulphur dioxide pollution. |
| B. | By carbon monoxide pollution. |
| C. | By pesticide pollution. |
| D. | By dust particles. |
| Answer» B. By carbon monoxide pollution. | |
| 320. |
The heating up of the earth's atmosphere due to the trapping of sun's heat rays by green house gases in the atmosphere is called: |
| A. | Light house effect |
| B. | Environmental pollution |
| C. | Greenhouse effect |
| D. | All the above |
| E. | None of these |
| Answer» D. All the above | |
| 321. |
Refer to the given food web. If a non-biodegradable insecticide known as DDT was sprayed onto the pine tree, in which of the following organisms will most of the DDT eventually accumulate? |
| A. | Golden-crowned kinglet |
| B. | Snake |
| C. | Red-tailed hawk |
| D. | Oak acorns |
| Answer» C. Red-tailed hawk | |
| 322. |
From which of the following bad effects does the ozone layer in our atmosphere protect us? |
| A. | Carbon dioxide |
| B. | CFC's |
| C. | The sun's ultraviolet rays |
| D. | All of the above |
| Answer» D. All of the above | |
| 323. |
Water fit for drinking is known as: |
| A. | Potable water |
| B. | Portable water |
| C. | Organic water |
| D. | Blue water |
| E. | None of these |
| Answer» B. Portable water | |
| 324. |
The 'greenhouse effect' refers to the |
| A. | Building up of pollution in the atmosphere |
| B. | Gradual warming of the Earth's atmosphere |
| C. | Hole in the ozone layer |
| D. | Increase in human population on Earth |
| Answer» C. Hole in the ozone layer | |
| 325. |
How are lead particles released into the air? |
| A. | By burning coal in thermal power stations |
| B. | By burning petrol in automobiles |
| C. | By burning biomass in chullahs |
| D. | By burning LPG for cooking |
| Answer» C. By burning biomass in chullahs | |
| 326. |
What is the effect of sulphur dioxide present in air on human beings? |
| A. | Harms the skin and the lungs |
| B. | Mixes with the blood and prevents it from carrying oxygen |
| C. | Affects the heart and the liver |
| D. | Raises the air temperature |
| Answer» B. Mixes with the blood and prevents it from carrying oxygen | |
| 327. |
Which of the following gases is regarded as an atmospheric pollutant? |
| A. | \[{{O}_{2}}\] |
| B. | \[{{O}_{3}}\] |
| C. | \[S{{O}_{2}}\] |
| D. | \[{{N}_{2}}\] |
| Answer» D. \[{{N}_{2}}\] | |
| 328. |
The depletion of oxygen due to excessive plant growth by the enrichment of nutrients in water is: |
| A. | Electrolysis |
| B. | Eutrophication |
| C. | Biodegradation |
| D. | Chlorination |
| E. | None of these |
| Answer» C. Biodegradation | |
| 329. |
Consider the following statements and select the option which correctly identifies true (T) and false (F) ones.(i) Scrubbers are used to remove suspended particulate matter from factories.(ii) Excess carbon monoxide present in the atmosphere traps a lot of heat and leads to warming of Earth's surface.(iii) The suspended particulate matter present in the air is known as aerosol.(iv) Kyoto protocol was signed to reduce the emission of greenhouse gases. |
| A. | (i)(ii)(iii)(iv)TFTF |
| B. | (i)(ii)(iii)(iv)TFFT |
| C. | (i)(ii)(iii)(iv)FFTT |
| D. | (i)(ii)(iii)(iv)TFTT |
| Answer» E. | |
| 330. |
The pie chart given below shows the composition of different gases in air. Identify gases W, X and Y |
| A. | W X Y Nitrogen Rare gases Oxygen |
| B. | W X Y Carbon Oxygen Rare gases |
| C. | W X Y Nitrogen Oxygen Rare gases |
| D. | W X Y Rare gases Hydrogen Oxygen |
| Answer» D. W X Y Rare gases Hydrogen Oxygen | |
| 331. |
What causes the dough to rise when yeast is added to it? |
| A. | An increase in temperature |
| B. | An increase in the amount of substance |
| C. | An increase in the amount of released water by yeast cells |
| D. | The release of carbon dioxide gas |
| Answer» E. | |
| 332. |
Study the given figures and select the correct statements regarding these. (i) Organism P is a unicellular green alga. (ii) Organism Q is a parasitic protozoan. (iii) Organism Q causes diseases in human beings. (iv) Both the organisms P and Q cannot synthesise their own food. |
| A. | (i) and (ii) only |
| B. | (ii), (iii) and (iv) only |
| C. | (i), (ii) and (iii) only |
| D. | (i), (ii), (iii) and (iv) |
| Answer» D. (i), (ii), (iii) and (iv) | |
| 333. |
Which of the following microorganisms play an important role in maintaining the balance of nitrogen gas in the atmosphere? |
| A. | Viruses |
| B. | Bacteria |
| C. | Algae |
| D. | Protozoa |
| Answer» C. Algae | |
| 334. |
A bacteria undergoes binary fission in every minute. This bacterium can fill up a cup in 1 hour. In how much time will the cup be half filled? |
| A. | 30 minutes |
| B. | 59 minutes |
| C. | 20 minutes |
| D. | 40 minutes |
| Answer» C. 20 minutes | |
| 335. |
The moist bread becomes mouldy after a few days when it is left in a container with a cover. Which of the following conditions favour the growth of the fungus? |
| A. | Absence of light |
| B. | Absence of water |
| C. | Presence of sunlight |
| D. | Presence of carbon dioxide |
| Answer» C. Presence of sunlight | |
| 336. |
Which of the following characteristics places algae in the group of autotroph? |
| A. | Carrying out anaerobic respiration |
| B. | Manufacturing their own food |
| C. | Feeding on dead organisms |
| D. | Feeding on other living organisms |
| Answer» C. Feeding on dead organisms | |
| 337. |
Consider the following statements and select the option which correctly identifies true (T) and false (F) ones.(i) Diatoms are marine algae which float in water due to the presence of light storage fats with silica.(ii) AIDS virus kills WBC and reduces immunity of the body.(iii) Escherichia coli is present in intestine of human where they help in digestion of food.(iv) A virus always consists of double strands of DNA or RNA surrounded by protein coat. |
| A. | (i)(ii)(iii)(iv)TFTF |
| B. | (i)(ii)(iii)(iv)TTTF |
| C. | (i)(ii)(iii)(iv)TTFF |
| D. | (i)(ii)(iii)(iv)TFTT |
| Answer» C. (i)(ii)(iii)(iv)TTFF | |
| 338. |
Which of the following statements describes bacteriophage correctly? |
| A. | It is a bacterium which causes diseases in plants. |
| B. | It is a type of virus which attacks bacteria. |
| C. | It is a bacterium which kills viruses. |
| D. | It can multiply inside both living and non-living cells. |
| Answer» C. It is a bacterium which kills viruses. | |
| 339. |
Which of the following pair is correct? |
| A. | Pathogens Diseases caused Viruses Dengue fever |
| B. | Pathogens Diseases caused Bacteria Malaria |
| C. | Pathogens Diseases caused Fungi Hepatitis |
| D. | Pathogens Diseases caused Protozoa Syphilis |
| Answer» B. Pathogens Diseases caused Bacteria Malaria | |
| 340. |
Observe the given figure and identify P, Q, R and S. |
| A. | P-Coccus, Q-Bacillus, R-Vibrio, S-Spirillum |
| B. | P-Bacillus, Q-Coccus, R-Spirillum, S-Vibrio |
| C. | P-Bacillus, Q-Vibrio, R-Coccus, S-Spirillum |
| D. | P-Bacillus, Q-Spirillum, R-Vibrio, S-Coccus |
| Answer» C. P-Bacillus, Q-Vibrio, R-Coccus, S-Spirillum | |
| 341. |
Which of the following microorganisms are used in making antibiotics? |
| A. | Viruses |
| B. | Fungi |
| C. | Bacteria |
| D. | Both and |
| Answer» E. | |
| 342. |
Which of the following organisms can perform photosynthesis? |
| A. | Euglena |
| B. | Paramecium |
| C. | Mucor |
| D. | Mushroom |
| Answer» B. Paramecium | |
| 343. |
Which of the following substances is/are produced by an organism to prevent or reduce the spread of microorganisms? |
| A. | Antiseptics |
| B. | Antibiotics |
| C. | Antibodies |
| D. | All of these |
| Answer» D. All of these | |
| 344. |
Which of the following organisms have an ability to help in recycling of nutrients and energy? |
| A. | Bacteria |
| B. | Diatoms |
| C. | Virus |
| D. | Fungi |
| Answer» B. Diatoms | |
| 345. |
Which of the following is the largest bacteria? |
| A. | Bacillus |
| B. | Coccus |
| C. | Spirillum |
| D. | Spherical |
| Answer» B. Coccus | |
| 346. |
Which of the following is represented by 'X' in the figure given below? |
| A. | Protozoa |
| B. | Bacteria |
| C. | Viruses |
| D. | Algae |
| Answer» D. Algae | |
| 347. |
Through which of the following modes do most of the infectious diseases spread? |
| A. | Body contact |
| B. | Air |
| C. | A vector |
| D. | All of these |
| Answer» E. | |
| 348. |
Refer to the given diseases.(i) Athlete's foot (ii) Amoebic dysentery(iii) Polio(iv) Cholera(v) Malaria(vi) Measles(vii) Pyorrhea(viii) Ringworm(ix) Typhoid(x) TuberculosisSelect the option which correctly identifies bacterial diseases (P), viral diseases (Q), protozoan diseases (R) and fungal diseases (S). |
| A. | PQRS(iii), (iv), (v)(ix), (x)(i), (ii), (v)(vii), (viii) |
| B. | PQRS(iii), (vi), (x)(iv), (ix)(ii), (v), (viii)(i), (vii) |
| C. | PQRS(iv), (vii), (ix), (x)(iii), (vi)(ii), (v)(i), (viii) |
| D. | PQRS(iv), (vi), (x)(iii), (ix)(ii), (v), (vii)(i), (viii) |
| Answer» D. PQRS(iv), (vi), (x)(iii), (ix)(ii), (v), (vii)(i), (viii) | |
| 349. |
Identify bacteriophage. |
| A. | Algae |
| B. | Virus |
| C. | Protozoa |
| D. | Fungi |
| Answer» C. Protozoa | |
| 350. |
A microorganism X is used in the making of bread. It is also used in making which of the following substances? |
| A. | Cheese |
| B. | Vinegar |
| C. | Wine |
| D. | Yoghurt |
| Answer» D. Yoghurt | |