Biology · Environmental Studies

Ecosystem Nutrition and Energy Flow

1,093 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 evs insectivorous plants meaning of an ecosystem food chain and food web components of environment and their interdependencies

Of the total amount of energy that passes from one trophic level to another, about 10% is

  1. Respired and becomes heat

  2. Passed out as faeces or urine

  3. Stored as body tissue

  4. Recycled to autotrophs
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The trophic level of an organism is the position it occupies in a food chain. The amount of energy at each trophic level decreases as it moves through an ecosystem. As little as 10 percent of the energy at any trophic level is transferred to the next level; the rest is lost largely through metabolic processes as heat. If a grassland ecosystem has 10,000 kilocalories (kcal) of energy concentrated in vegetation, only about 1,000 kcal will be transferred to primary consumers, and very little (only 10 kcal) will make it to the tertiary level. Energy pyramids such as this help to explain the trophic structure of an ecosystem.

So the correct option is 'Stored as body tissue'.

Multiple choice evs - i insectivorous plants meaning of an ecosystem food chain and food web components of environment and their interdependencies

The interlocking pattern of various food chains is referred as food web.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In nature, some organisms operate in the ecosystem not just at a single trophic level but more than one trophic levels which means that it may derive its food from more than one source. The organism may get eaten itself by another organism of higher trophic level. It may also feed on different organisms of lower trophic levels. In this way, various food chains are linked together in an ecosystem and the intersection of these food chains form a complex network called food web. 

Hence, the statement given in the question is correct.
So, the correct answer is 'True'.

Multiple choice evs insectivorous plants meaning of an ecosystem food chain and food web components of environment and their interdependencies

Trophic levels in ecosystem are formed by

  1. only bacteria

  2. only plants

  3. only herbivores

  4. organisms linked in food chain
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Trophic levels in an ecosystem are formed by organisms linked in food chain. It starts from producer level and usually ends at secondary or tertiary consumer levels.

So, the correct answer is option D, organisms linked in food chain.

Multiple choice evs - i insectivorous plants meaning of an ecosystem food chain and food web components of environment and their interdependencies

The study of food chains and food webs is observed in the phenomenon known as

  1. biological chain

  2. ecosystem

  3. biological magnification

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

Biological magnification (or biomagnification) refers to the increasing concentration of substances, such as toxic chemicals, at higher trophic levels of a food chain or food web.

Multiple choice evs - i insectivorous plants meaning of an ecosystem food chain and food web components of environment and their interdependencies

Tree $\rightarrow$ Caterpillar $\rightarrow$ Robin $\rightarrow$ Cat represents a food chain. In this food chain, if the tree can provide 100000 calories of energy, how much calories of energy will be available to the robin and the cat?

  1. 10000 and 1000 calories, respectively

  2. 1000 and 100 calories, respectively

  3. 1000 and 10000 calories, respectively

  4. 100 and 1000 calories, respectively
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The amount of energy flow decreases with every successive trophic level and only 10% is passed to the next level as useable biological energy and the rest 90% is lost in the transfer. So, in the given case, 1,00,000 calories of energy  is with producer that is the tree and thus caterpillar will have 10,000, robin will have 1,000 and the energy available with cat will be 100 calories.
So, the correct answer is option B.
Multiple choice evs insectivorous plants meaning of an ecosystem food chain and food web components of environment and their interdependencies

In an aqueous environment, microscopic animals and plants are collectively known as

  1. Herbivores

  2. Fauna and flora

  3. Planktons

  4. Symbionts
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Planktons are the small or microscopic organisms that drift or swim weakly in a body of water, including bacteria, diatoms, jellyfish and various larvae. Plankton is an important food source for fish and other larger organisms. They cannot swim against a current.

Therefore, the correct answer is option C.

Multiple choice evs - i insectivorous plants meaning of an ecosystem food chain and food web components of environment and their interdependencies

What is correct about food chain and food web?

  1. The food chain is a series of organisms feeding on one another, food web consists of a number of interlinked food chains.

  2. The food chain is a series of plants feeding on one another, food web consists of a number of interlinked chains.

  3. The food chain is a series of plant feeding, food web consists of a number of interlinked nets.

  4. The food chain is a series of plants feeding on one another, food web consists of a number of food.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • A food chain is a linear path in which an organism gets food, it starts with plants and ends with animals. A network of many food chains is called a food web. 
  • A food web consists of all the food chains in a single ecosystem. Each living thing in an ecosystem is part of multiple food chains. 
  • Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem. All of the interconnected and overlapping food chains in an ecosystem make up a food web.

Thus, the correct answer is option A.

Multiple choice zoology energy flow in an ecosystem the energy pyramid ecological pyramid ecological pyramids

Which one statement for pyramid of energy is incorrect?

  1. Inverted in shape

  2. Upright in shape

  3. Base is broad

  4. Shows energy content of different trophic levels
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pyramid of energy represents the amount of energy at different trophic level. It is always upright in shape. Only 10% of energy is transferred from one trophic level to next trophic level. The majority of energy is lost during the transfer of energy. The base of pyramid of energy is always broad indicating maximum amount of energy at the first trophic level. 

Thus, the correct answer is 'Inverted in shape.'

Multiple choice zoology energy flow in an ecosystem the energy pyramid ecological pyramid ecological pyramids

Which of the following is not a limitation of pyramid?

  1. It does not take into account the same species belonging to two or more trophic level

  2. It does not accommodate a food chain

  3. It does not accommodate a food web

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ecological pyramids have limitations, one of which is that they do not account for species that occupy multiple trophic levels, such as omnivores.

Multiple choice zoology energy flow in an ecosystem the energy pyramid ecological pyramid ecological pyramids

Which of the following is not limitation of pyramid?

  1. It does not take into account the same species belonging to two or more trophic level

  2. It does not accommodate a food chain

  3. It does not accommodate a food web

  4. Saprophytes are given any place
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Similar to the previous question, a major limitation of ecological pyramids is their inability to represent species that function at more than one trophic level simultaneously.

Multiple choice zoology energy flow in an ecosystem the energy pyramid ecological pyramid ecological pyramids

Pyramid of energy is always upright indicating that

  1. Producers have the lowest energy conversion efficiency.

  2. Carnivorous have a better energy efficiency than herbivores.

  3. Energy conversion efficiency is same for all trophic levels.

  4. Herbivores have a better energy conversion efficiency than carnivores.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pyramid of energy represents the amount of energy at each trophic level. In any ecosystem, flow of energy declines as it passes from lower to higher trophic level. Hence, pyramid of energy is always upright indicating that herbivores have a better energy conversion efficiency than carnivores.  Each successive trophic level has less total energy. In this, the energy decreases from one trophic level to the next trophic level because energy is lost as metabolic heat during transfer of energy. When food energy passes from producers to herbivores to carnivores, only 10% of energy is transferred from one trophic level to another trophic level.

Thus, the correct answer is 'Herbivores have a better energy conversion efficiency than carnivores.'

Multiple choice zoology energy flow in an ecosystem the energy pyramid ecological pyramid ecological pyramids

According to Charles Elton, which is not correct?

  1. Carnivores are at the top of the pyramid.

  2. Energy trapping is high at the top of the pyramid.

  3. Producers at the top of the pyramid.

  4. Both B and C.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Correct answer-(D)

Charles Elton, an English biologist, developed the idea of ecological pyramids. These pyramids are therefore also termed as Eltonian pyramids. An ecological pyramid may be defined as a graphic representation of the numbers or biomass or status of accumulated energy at different trophic levels in a food chain in an ecosystem. The Eltonian pyramid is a concept which relates to food consumption efficiency. According to Charles Elton, carnivores are at the top of the pyramid. Producers are at the bottom of the pyramid. They manufacture food and provide nutrition for the next level. Energy trapping is high at the base of the pyramid, i.e., producer level. The energy is highest at the producer level as it traps energy from the sun. It gradually decreases as one moves to subsequent levels, i.e. herbivores and different carnivores.

Multiple choice zoology energy flow in an ecosystem the energy pyramid ecological pyramid ecological pyramids

Choose the correct answers from the alternatives given :
One of the lessons from an energy pyramid is that

  1. only one-half of the energy in one trophic level is passed on to the next level

  2. the energy lost as heat or in cellular respiration is 10% of the available energy of each trophic level

  3. ecological efficiency is highest for primary consumers

  4. eating grain-fed beef is an inefficient means of obtaining the energy trapped by photosynthesis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

An energy pyramid is the graphical representation of energy flow in a particular community. The different trophic levels represent a different group of animals. Here only ten percent of the energy is passed on to the next trophic level. As the organism of one trophic level is consumed by the organism of the next trophic level, energy decreases as it goes up the trophic level. So, the correct answer is "eating grain-fed beef is an inefficient means of obtaining the energy trapped by photosynthesis".