23. Organisms at the base of the food chain are:
(a) Photosynthetic plants(b) Decomposers(c) Carnivores(d) Herbivores
23. Organisms at the base of the food chain are: Read More »
22. The maximum biological magnification of DDT through food web is seen in:
(a) Algae(b) Bacteria(c) Man(d) Higher plants
22. The maximum biological magnification of DDT through food web is seen in: Read More »
21. Which of the following is usually not an air pollutant?
(a) Hydrocarbons(b) Nitrous oxide(c) Sulphur oxide(d) Carbon dioxie
21. Which of the following is usually not an air pollutant? Read More »
20. The main factor which determines the balance of nature is:
(a) Human activities(b) Habit and habitat(c) Environmental pollution(d) Availability of food
20. The main factor which determines the balance of nature is: Read More »
19. The crop most susceptible to frost is:
(a) Wheat(b) Cotton(c) Red gram(d) Black gram
19. The crop most susceptible to frost is: Read More »
18. Which of the following fuels causes minimum environmental pollution?
(a) Diesel(b) Kerosene(c) Hydrogen(d) Coal
18. Which of the following fuels causes minimum environmental pollution? Read More »
17. A microscopic organism playing a vital role in nitrogen cycle is:
(a) Virus(b) Bacteria(c) Protozoa(d) Red algae
17. A microscopic organism playing a vital role in nitrogen cycle is: Read More »
16. Nitrogen fixation is done by:
(a) Red algae(b) Blue green algae(c) Brown algae(d) None of these
16. Nitrogen fixation is done by: Read More »
15. Which of the following gases is not found free in air?
(a) Nitrogen(b) Hydrogen(c) Oxygen(d) Carbon dioxide
15. Which of the following gases is not found free in air? Read More »
14. Biodegradable wastes can usually be converted into useful substances with the help of
(a) Bacteria(b) Nuclear proteins(c) Radioactive substances(d) None of these