IAS Questions of Environment and Ecology-Set 10 for Prelims Exam

1.    Ecological event marked by an enormous increase in the number of some kinds of organism is termed as

(a)    Biostasy         (b) Geological transition  
(c)     Ecological explosion     (d) Community explosion

Ans:- (c)  Ecological explosion

Exp. - Defined in 1958 by Elton, Ecological event marked by an enormous increase in the number of some kinds of organism is termed as Ecological explosion e.g epidemics of infections viruses and bacteria, such as influenza, bubonic pique etc

2.     The transition on the ground between two plant communities is known as

(a)    Ecotone     (b) Biota  
(c)    Ecotope      (d) Biotope

Ans:- (a) Ecotone

Exp. - The transition on the ground between two plant communities is known as Ecotone. It may be a broad zone and reflect a gradual blending of two communities or may be approximated by sharp boundary line.

3.    The entire component of species of organism plants and animals, found within a given region is called

(a)    Habitat     (b)    Niche   
(c)    Community     (d)    Biota

Ans:-  (d) Biota

Exp. -The entire component of species of organism plants and animals, found within a given region is known as Biota.

4.    Components of an ecosystem include

(a)    Biotic     (b) Abiotic    
(c)    Both     (d) None

Ans:- (c)  Both

Exp. Ecosystem is group of organisms and the environment within which the organisms interact. It consists of both biotic (living) and Abiotic (None living) components.

5.    The synthesis of organic compounds from inorganic compounds utilizing energy stored in inorganic substance is called :-

(a)    Photo synthesis    (b)    Chemosynthesis     
(c)     Respiration        (d)    None

Ans:- (b)  Chemosynthesis

Exp.-The synthesis of organic compounds from inorganic compounds utilizing energy stored in inorganic substance is called chemosynthesis. Such as Sulphur, ammonia and hydrogen. Energy is released when these substances are oxidized. Organisms at the bottom of ocean and in dark caves develop through this process.

6.    Plants and microorganisms that are capable of photosynthesis are called

(a)    Autotrophs     (b) Heterotrophs   
(c)    Detritus    (d) None

Ans:- a) Autotrophs

Exp.-Plants and microorganisms that are capable of photosynthesis are called Autotrophs. Produces also include microorganism such as bacteria near oceans vents that are capable of chemosynthesis.  

7.    The cycling, at various scales, of minerals and components through the ecosystem is known as

(a)    Biological cycle    (b)    Biogeochemical cycle   
(c)    Biochemical cycle       (d)    None

Ans:- b)  Biogeochemical cycle    

Exp. – The cycles (carbon and nitrogen cycle) involves phases of weathering of rocks, uptake and storage by organisms and return to the pool of soil, the atmosphere or ocean sediments.

8.    The greatest pool of the earth’s total carbon is found in which of the following sources?

(a)    Atmosphere    (b)    Ocean    
(c)    Soil     (d)    Lakes & Rivers

Ans:- (b) Ocean        

Exp.    About 93% of earth’s total carbon is found in the ocean all of this carbon is bound chemically in carbon dioxide. The ocean absorbs carbon dioxide through photosynthesis by small plankton.

9.    By which of the following activities, carbon dioxide is produced in the atmosphere?

(a)    Volcanic activity      
(b)    Respiration by human beings   
(c)     Fossil fuel combustion  
(d)    All of the above

Ans:- (d)  All of the above

Exp: Carbon dioxide is produced in the atmosphere by all the above mentioned activities.

10.    Cycle of which of the following atmospheric gases involves the major constituent of the atmosphere?

(a)    Oxygen     (b)    Carbon Dioxide    
(c)    Argon     (d)    Nitrogen

Ans:- (d) Nitrogen

Exp. The nitrogen cycle involves the major constituent of the atmosphere, 78.084% of each breath we take. It is also an important element in the formation of organic molecules especially proteins, and therefore is essential to living process.