Tag: species, communities and ecosystems

Questions Related to species, communities and ecosystems

The flow of materials from non living components to living components and back to the non living components in a more or less cyclic manner is called as

  1. Gaseous cycle

  2. Sedimentary cycle

  3. Biogeochemical cycle

  4. Hydrologic cycle


Correct Option: C
Explanation:

A biogeochemical cycle or inorganic-organic cycle is a circulating or repeatable pathway by which either a chemical element or a molecule moves through both biotic (bio-) and abiotic (geo-) compartments of an ecosystem. 

Source of maximum sulphur in reservoir of sulphur is

  1. Ocean

  2. Lakes

  3. Rocks

  4. Both A and C


Correct Option: D
Explanation:

The ocean represents a major reservoir of sulphur on earth, with large quantities in the form of dissolved sulphate and sedimentary minerals (e.g., gypsum and pyrite). Sulphate is the most stable form of sulphur on earth; weathering and leaching of rocks and sediments are its main sources to the ocean. The majority of sulphur is found in seawater or sedimentary rocks especially pyrite rich shales and evaporite rocks. 

Therefore, the correct answer is option D.

Biogeochemical cycles are also known as

  1. Cycles of matter

  2. Sedimentary cycles

  3. Material cycling

  4. Gaseous cycles


Correct Option: A
Explanation:

Biogeochemical cycles may also be referred to as cycles of matter because they link together all organisms and abiotic features on earth. Matter is continually recycled among living and abiotic elements on earth. Biogeochemical cycles facilitate the transfer of matter from one form to another and from one location to another on planet earth.

Therefore, the correct answer is option A.

Biogeochemical cycles can be traced in 

  1. Ecosystems

  2. Biomes

  3. Only water

  4. Both A and B


Correct Option: D
Explanation:

Biogeochemical cycles are the nutrient cycles. These are the cycles which are responsible for the recycling of the nutrients. The chemical cycles are necessary for the metabolism and maintenance of the organisms in the ecosystem. Biome is a collection of many ecosystems. The nutrient recycling takes place in the ecosystem and biomes. 

Thus, the correct answer is option D. 

The natural cycle that circulates elements between the earth and the environment is called as 

  1. Biological cycle

  2. Chemical cycle

  3. Biogeochemical cycle

  4. None of the above


Correct Option: C
Explanation:

Biogeochemical cycles are the nutrient cycles. These are the cycles which are responsible for the recycling of the nutrients which are present in the geosphere and atmosphere. The nutrient recycling takes place in the ecosystem and biomes. The recycling of nutrients helps in maintaining the nutrients in the available form for the uptake by the organisms.

Thus, the correct answer is option C.  

Which of the following is a sedimentary cycle?

  1. Carbon

  2. Hydrogen

  3. Nitrogen

  4. Phosphorus


Correct Option: D
Explanation:

The abiotic components which are recycled without any involvement of the gaseous form are known as the sedimentary cycle. The element is present in the form of salts as rocks in the geosphere which is taken up by the plants and then transferred to the animals. The phosphate is generally transferred and used in the form of ATP by the living cells. 

Thus, the correct answer is option D. 

Plant maintains the balance of ......... in the atmosphere.

  1. Oxygen

  2. Carbon dioxide

  3. Oxygen and Carbon dioxide

  4. None of these


Correct Option: C
Explanation:

Photosynthesis is the process in which autotrophs such as green plants use carbon dioxide and water in presence of sunlight to synthesize nutrients such carbohydrates in the form of glucose and release oxygen. Hence oxygen is returned to the atmosphere by photosynthesis. This oxygen from the atmosphere is taken in by animals for carrying out the process of respiration and carbon dioxide is evolved. This carbon dioxide is used by plants and the same cycle continues. Hence plants maintain the balance of oxygen and carbon dioxide in the atmosphere. Thus the correct answer is option C.

An ecosystem, such as an aquarium, is self-sustaining if it involves the interaction between organisms, a flow of energy, and the presence of 

  1. Equal numbers of plants and animals

  2. More animals than plants

  3. Materials cycles

  4. Pioneer organisms


Correct Option: C
Explanation:

If a ecosystem such as an ecosystem is to be self-sustaining, materials such as oxygen, carbon dioxide, water and nitrogen must be able to recycle between the organisms. 

Therefore, the correct answer is option C.

The conversion of $\displaystyle $ is known as

  1. Denitrification

  2. Nitrification

  3. Nitrogen fixation

  4. Ammonification


Correct Option: A
Explanation:
The process of conversion of free nitrogen from the atmosphere into soluble nitrates by microorganisms is  known as biological nitrogen fixation. 
When plants and animals die, the nitrogenous compounds present in their bodies are broken down into  ammonia. This process is known as ammonification.  Ammonia is converted to nitrates by nitrifying bacteria, such as Nitrosomonas and Nitrobacter, through a  process called nitrification.
Nitrification is followed by denitrification, wherein nitrates are converted into nitrogen gas (N2), by the  action of denitrifying bacteria such as species of Nitrosomonas, Pseudomonas, Alcaligenes and Bacillus.  The nitrogen gas is then released into the atmosphere.

Biogeochemical cycles

  1. Include the processes only conducted by or within living organisms

  2. Pertain only to the abiotic environment

  3. Describe the movement of water and other materials throughout the abiotic and biotic environment

  4. Are used to describe the attempts of humans to recycle various pollutants


Correct Option: C
Explanation:
Breaking apart the word biogeochemical into pieces. The first part of the word, bio, involves biological organisms, like bacteria, plants, and animals. The next part of the word, geo, involves geological processes, like the weathering of rocks. The last part of the word indicates chemical processes, such as the formation of molecules. Thus a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical substance moves through both biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) compartments of Earth. A cycle is a series of change which comes back to the starting point and which can be repeated.
So, the correct answer is 'Describe the movement of water and other materials throughout the abiotic and biotic environment'.