Biology · Environmental Studies

Ecosystem Nutrition and Energy Flow

1,235 Questions

Ecosystem nutrition and energy flow questions cover trophic levels, food chains, and biodegradable materials. These concepts frequently appear in general science sections of major competitive exams. Review these questions to build a solid understanding of ecological interactions.

Trophic levels conceptFood chain orderAutotrophic nutritionEnergy assimilationScavengers and decomposers

Ecosystem Nutrition and Energy Flow Questions

Multiple choice

Which of the following statements is/are correct about plants?

  1. In a food chain, plants are known as 'producers of energy'.
  2. All plants are categorized under the autotrophic mode of nutrition.
  3. Plants follow the '20% law of transfer of energy'.

  1. Only 1

  2. Only 2

  3. Only 1 and 3

  4. Only 2 and 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

(1) Plants are called 'producers of energy' because they start the food chain by synthesizing food in the presence of sunlight.

(2) Not all plants are categorized under autotrophic mode of nutrition. There are some carnivorous plants also, which trap insects and get nutrition from them. For example, Drosera, Venus Flytrap and Nepenthes.
(3) All trophic levels of a food chain follow the 'ten percent law', i.e. only about 10% energy is transferred from one trophic level to the next trophic level.

Multiple choice

Ratio between the energy flow at various points along the food chain, when represented as percentage, is known as

  1. ecological efficiency

  2. ecological gradient

  3. relative ratio of energy flow

  4. energy flow efficiency
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ratio between the energy flows at various points along the food chain when represented as percentage is known as 'ecological efficiency' which describes the efficiency with which the energy is transmitted from one trophic level to the next.

Multiple choice

Which of the following statements is/are correct?

a. Oxygen is an essential component of most biological molecules like carbohydrates, proteins, nucleic acids and fats (or lipids). b. Oxygen from the atmosphere is used up in the processes of combustion and respiration, and in the formation of oxides of nitrogen. c. The process of nitrogen fixation by bacteria takes place in the presence of oxygen.

  1. Only a

  2. Only b

  3. Only c

  4. Both a and b

  5. a, b and c
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct answer. Oxygen is an essential component of most biological molecules like carbohydrates, proteins, nucleic acids and fats (or lipids). Oxygen from the atmosphere is used up in the processes of combustion and respiration, and in the formation of oxides of nitrogen.

Multiple choice

Which of the following statements is/are correct?

a. Flow of energy in biosphere is unidirectional. b. Energy once trapped gets converted into proteins during its passage through trophic levels of the chain. c. Amount of minerals cycling through living and non-living components remains constant.

  1. a, b and c

  2. a and b

  3. a and c

  4. only a

  5. only b
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct answer as both statements are correct. Flow of energy in biosphere is unidirectional from non-living to living things. Amount of minerals cycling through living and non-living components remains constant.

Multiple choice

In a newly grown pond or lake, the development of similar biotic communities is called hydrosere. What are the sucession stages of hydrosere?

  1. primary, secondary & finally matured

  2. Seed Germination, development of vegetation, flowering & seed- development of fruits, matured plants

  3. Preparing and completing compost, spawning, casing, pinning and cropping

  4. Phytoplankton, rooted submerged, floating, reed-swamp, sedge meadow, woodland and climax stage

  5. Germination, seedling, growth of vegetation, preflowering followed by flowering and finally seed
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Phytoplankton stage is composed of pioneers or primary colonizers, which include green algae, blue-green algae, diatoms, bacteria. In rooted submerged stage at the bottom of such water bodies, soft mud is formed due to diminution & decomposition of phytoplankton. In floating stage, the root of the plants are fixed firmly and leaves float at the surface of water. In reed-swamp stage, though the plants are rooted but most parts of their young branches are uncovered & exposed to environment. In sedge meadow stage, water level is decreased rapidly due to excess transpiration & the soft mud portion begins to expose. In woodland stage, it becomes dry over the time. Forest stage is ultimate stage where dense vegetation is developed forming dense forest.

Multiple choice

What is detritus food chain?

Grazing food chain supplements energy to the ecosystem. It imposes inorganic nutrients. Detritus food chain obtains food energy from the detritus & prevents its loss. It helps in emitting inorganic nutrients for cycling.

  1. Transmission of energy from one trophic level to the next.

  2. Detritus food chain starts with organic matter that are no longer alive & move through the detritus feeding organisms in land to those organisms which are detritus feeders.

  3. Graphical representation of trophic structure & functions at consecutive trophic level.

  4. Various interconnected food chains through which food energy is transmitted to the ecosystem.

  5. It is the chain of debris.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Detritus food chain starts with organic matter that are no longer alive & move through the detritus feeding organisms in land to those organisms which are detritus feeders.

Multiple choice

What is grazing food chain?

Grazing food chain supplements energy to the ecosystem. It imposes inorganic nutrients. Detritus food chain obtains food energy from the detritus & prevents its loss. It helps in emitting inorganic nutrients for cycling.

  1. Food chain made by grazing animals.

  2. Number of different related food chains where the food energy is passed to the ecosystem.

  3. It begins with green vegetation & transfers to herbivorous primary consumers & ultimately ends with carnivores.

  4. It is the transmission of energy by grazing animals.

  5. It is a chain of different food items for grazing animals.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Grazing food chain begins with green vegetation & transfers to herbivorous primary consumers & ultimately ends with carnivores.