FREE NEET Biology Practice MCQ Test: Ecosystem Exercise 1 Questions Answers With Detailed Explanations [PDF]

Answer: (d)

Answer: (d)

Answer: (b)

Anaerobiosis inhibits or slow down decomposition process. It is the complete absence or loose of gaseous or dissolved elemental oxygen in a given place or environment. For decomposition, oxygen is required by detritivores (i.e. microorganisms). Thus, if there is the absence of oxygen, decomposition will be inhibited.

Answer: (b)

It feeds upon grains hence called primary consumer and can also feed on insects hence called secondary consumer at the same time in the same ecosystem.

Answer: (d)

The cycling pool of carbon consists of 6 × $10^{14}$ kg (29%) of free $CO_2$ in the atmosphere, 1.45 × $10^{15}$ kg (71%) of dissolved $CO_2$ occurs in the oceans. Oceans also regulate the amount of $CO_2$ in the atmosphere.

The cyclic movement of the elements from the abiotic system to the biotic system and back again is the biogeochemical cycle. These chemicals form the compounds of food, so these are also known as nutrient cycles.

Some of the important biogeochemical cycles are carbon cycle, Oxygen cycle nitrogen cycle, Phosphorus cycle.

Following aspect are studied in biogeochemical cycling-

The nature and size of the natural reservoir

The rate of movement between reservoirs

The interaction between different biogeochemical cycles

The correct option is the 'creation of their own biogeochemical cycles by new species'

Answer: (c)

The given diagram represents a simplified model of phosphorus cycle in a terrestrial ecosystem. The natural reservoir of phosphorus is rock, which contains the phosphorus in the form of phosphates.

Answer: (c)

Arrow III is incorrect.

Answer: (c)

Statement in option (c) is incorrect. It can be corrected as In the successive seral stages, there is a change in the diversity of species of organisms, increase in the number of species and organisms as well as an increase in the total biomass. Rest of the statements are correct.

Answer: (a)

Answer: (c)

Answer: (a)

In food web, each successive trophic level has less total energy content as per law of Lindeman. Some energy is lost in transfer from one to another level.

Answer: (b)

Answer: (d)

The gradual and predictable change, in the composition of species takes place in a given area during ecological succession.

Answer: (a)

Phosphorus is mostly used as phosphate. Its reservoir pool is phosphate rocks while cycling pool is soil for terrestrial ecosystems and water for aquatic ecosystems.

Answer: (c)

Answer: (b)

Sparrow feeds upon grains hence called primary consumer and can also feed on insects hence also called secondary consumer at the same time in the same ecosystem.

Answer: (c)

Answer: (b)

Answer: (c)

Answer: (b)

Statements II and IV are correct. Statements I and III are incorrect and can be corrected as

• Decomposition is an oxygen requiring process.
• Warm and moist environment favours decomposition.