Ecosystem Chapter-Wise Test 10

Correct answer Carries: 4.

Wrong Answer Carries: -1.

Which of the following is an incorrect statement about trophic levels?

Producers occupy the first trophic level
Herbivores belong to the third trophic level
Energy decreases at higher trophic levels
Carnivores feed on herbivores
2

Herbivores do not belong to the third trophic level; they are primary consumers and belong to the second trophic level.

What is the major role of decomposers in an ecosystem?

They fix atmospheric nitrogen
They break down organic matter into inorganic nutrients
They produce energy for primary consumers
They consume other organisms directly
2

Decomposers break down dead organic matter into inorganic nutrients, making them available for uptake by producers.

Which of the following is an incorrect statement about ecological pyramids?

Pyramids of energy are always upright
Pyramids of biomass in aquatic ecosystems are always upright
Pyramids of numbers can be inverted
Ecological pyramids represent trophic relationships
2

Pyramids of biomass in aquatic ecosystems can be inverted due to the rapid turnover of phytoplankton.

Which type of food chain is dominant in a terrestrial ecosystem?

Grazing food chain
Detritus food chain
Parasitic food chain
None of the above
2

In terrestrial ecosystems, most energy flows through the detritus food chain, where dead organic matter is decomposed and recycled.

Which of the following processes involves the breakdown of detritus into simpler inorganic substances?

Humification
Mineralization
Fragmentation
Leaching
2

Mineralization is the process in which decomposers break down complex organic substances into inorganic nutrients.

Which of the following is a correct statement about food chains?

Food chains always begin with consumers
Food chains represent the transfer of energy in an ecosystem
Food chains do not include decomposers
Food chains allow energy to cycle back to producers
2

Food chains illustrate the transfer of energy from producers to various levels of consumers.

Which of the following statements about the water cycle is incorrect?

Evaporation contributes to cloud formation
Transpiration plays a role in the water cycle
Groundwater is not a part of the water cycle
Precipitation returns water to the Earth's surface
3

Groundwater is an essential part of the water cycle, contributing to surface water bodies and maintaining ecosystems.

Which of the following is a correct statement about biological magnification?

Toxins decrease at higher trophic levels
Toxins accumulate and increase in concentration at higher trophic levels
It does not affect top predators
It has no relation to human activities
2

Biological magnification causes toxins to accumulate at higher trophic levels, affecting top predators the most.

Which of the following statements about trophic levels is correct?

Energy increases at higher trophic levels
Producers form the first trophic level
Herbivores belong to the third trophic level
Carnivores belong to the second trophic level
2

Producers occupy the first trophic level, as they convert solar energy into chemical energy through photosynthesis.

What percentage of Photosynthetically Active Radiation (PAR) is captured by plants?

100%
50%
10-20%
2-10%
4

Plants capture only 2-10% of the Photosynthetically Active Radiation (PAR) to carry out photosynthesis.

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