Tag: decomposition in ecosystem

Questions Related to decomposition in ecosystem

Choose the correct sequences.

  1. $CO _{2}$ in atmosphere $\rightarrow $ decomposers $\rightarrow $ organic carbon in animals $\rightarrow $ organic carbon in plants.

  2. $CO _{2}$ in atmosphere $\rightarrow $ organic carbon in plants $\rightarrow $ organic carbon in animals $\rightarrow $ inorganic carbon in soil.

  3. Inorganic carbonates in water $\rightarrow $ organic carbon in plants $\rightarrow $ organic carbon in animals $\rightarrow $ scavengers.

  4. Organic carbon in animals $\rightarrow $ decomposers $\rightarrow CO _{2}$ in atmosphere $\rightarrow $ organic carbon in plants.


Correct Option: B
Explanation:

Nutrient cycles circulate matter through the biosphere. The nutrients regularly alternate between living (biotic) and nonliving (abiotic) components. Hence the nutrient cycles are also called as biogeochemical cycles. The important nutrient cycles are water cycle, carbon cycle, nitrogen cycle, mineral cycle. In the carbon cycle, atmospheric carbon is fixed into organic compounds like carbohydrates by green plants during the process of photosynthesis. The organic compounds are consumed by heterotrophic organisms like animals. The waste materials of animals and dead bodies of animals and plants are acted upon by detrivorous organisms, releasing the mineral nutrients like carbon, nitrogen, sulphur etc back to the environment.

The slow rate of decomposition of fallen logs is due to

  1. poor nitrogen content

  2. anaerobic environment

  3. low cellulose contents

  4. low moisture contents


Correct Option: D
Explanation:

Low or reduced moisture alters and reduces the decomposition process. A slow rate of composition of fallen logs is likely due to low moisture contents.

So, the correct answer is option D, low moisture contents.

Which of the following factors is not limiting?

  1. CO$ _2$ concentration

  2. Light intensity

  3. Temperature

  4. Oxygen


Correct Option: D

Which association below is not correct?

  1. Cumulus congestus - anvil top

  2. Cumulus - fair weather cumulus

  3. Altocumulus castellanus - resemble "little castles"

  4. Stratus fractus - scud


Correct Option: A

Which one of the following is a major link in decomposer food chain?

  1. Anthracoceros

  2. Gyps

  3. Anser

  4. Pavo


Correct Option: B
Explanation:

Gyps is a genus of vultures characterized by bald head, broad wings and mainly dark plumage. They are large scavenging birds, feeding mostly from carcasses of dead animals and thereby forming an important link in the decomposes food chain.
Thus, the correct answer is (B) Gyps.

In summers, decomposition proceeds faster than in

  1. Spring

  2. Winter

  3. Autumn

  4. Hot weather


Correct Option: B

50% of incident energy is lost due to:

  1. Consumers

  2. Producers

  3. Microorganisms

  4. Planktons


Correct Option: B

Presence of hydrogen sulphide indicates anaerobic

  1. Decomposition

  2. Eutrophication

  3. Degradation

  4. Biodegradation


Correct Option: A

The correct match among the following is

  1. Producers--- act upon the decomposed substances and transform them into different forms of inorganic and organic substances

  2. Consumers--- are autotrophic members of ecosystem

  3. Decomposers--- feed upon dead decaying living organisms and break them into simpler compounds fit for use of producers

  4. None of the above


Correct Option: C
Explanation:

The green plant in the ecosystem-terminology are called as producers. All animals depend on plants (directly or indirectly) for their food needs. They are hence, called as consumers and also heterotrophs. 

Decomposers are organisms, that break down dead or decaying organisms, and carry out the natural process of decomposition. Like herbivores and predators, decomposers are heterotrophic, meaning that they use organic substrates to get their energy, carbon and nutrients for growth and development.

The breakdown of detritus into smaller particles by earthworm is a process called as

  1. Humification

  2. Fragmentation

  3. Mineralisation

  4. Catabolism


Correct Option: B
Explanation:

Steps of decomposition are: 

a. Fragmentation: It is the breakdown of detritus into smaller particles by detritivores (e.g., earthworm). 
b. Leaching: By this process, water soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts. 
c. Catabolism: Degradation of detritus into simpler inorganic substances by bacterial and fungal enzymes. Fragmentation, leaching and catabolism operate simultaneously on the detritus. 
d. Humification: Accumulation of humus (dark amorphous substance) in soil. Humus is resistant to microbial action and so decomposes very slowly.
e. Mineralization: It is the release of inorganic nutrients due to the degradation of humus some microbes.