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

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.

Multiple choice

Which mode of nutrition is found in houseflies?

  1. Autotrophic

  2. Saprophytic

  3. Holozoic

  4. Parasitism

  5. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Insects like houseflies secrete digestive juices on the food. The food is digested while it is still to be ingested.

Multiple choice

Which of the following options best represents the food chain?

  1. Sun-Cows-Lions-Grass

  2. Sun-Grass-Lions-Cows

  3. Sun-Grass-Cows-Lions

  4. Sun-Cows-Grass-Lions

  5. Lions-Cows-Grass-Sun
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the right option. Here grass is preparing food in the presence of sun, cows are eating grass and lions are eating cows as their food.

Multiple choice

The ant is _______.

  1. a carnivore

  2. a herbivore

  3. an omnivore

  4. a predator

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

The ant is an omnivore because it eats both plant and animal product.

Multiple choice

The transfer of energy through a terrestrial ecosystem is often depicted by energy pyramids. Which one of the following statement is true?

  1. ecological efficiency is highest for top consumers

  2. about 10% of the energy from one trophic level is incorporated into the biomass of the next level

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

  4. only 25% of energy in one trophic level is passed on to the next level
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The 10% rule is a fundamental principle of ecological energy transfer - only about 10% of energy from one trophic level is converted into biomass of the next level. The remaining 90% is lost primarily through respiration (as heat) and incomplete consumption/digestion. Ecological efficiency is actually lowest for top consumers due to cumulative energy losses, and energy transfer varies but averages around 10%, not exactly 25%.

Multiple choice

The length of the food chain in an ecosystem is generally limited to 3 - 4 trophic levels because

  1. quality of energy increases from lower to higher trophic levels

  2. quantity of energy decreases from lower to higher trophic levels

  3. quantity of energy increases from lower to higher trophic levels

  4. flow of energy is unidirectional

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Energy decreases at each trophic level due to inefficient energy transfer (approximately 10% efficiency), so higher trophic levels have progressively less energy available to support them. By the 3rd or 4th level, there's insufficient energy to sustain viable populations. Energy quality doesn't increase in a meaningful way, and while energy flow is unidirectional, that doesn't limit chain length - the quantitative energy loss does.

Multiple choice

Which of the following statements is/are correct?

a. In saprophytic nutrition, the organisms obtain their food from dead and decaying organic matter of dead plants, dead animals and other decaying matter. b. In parasitic nutrition, an organism (parasite) lives on the body surface or inside the body of another organism (known as a host) to derive its nutrition. c. In holozoic nutrition, the organism undergoes the process of internalization (ingestion) and internal processing of liquids or solid food particles.

  1. a, b and c

  2. a and b

  3. a and c

  4. b and c

  5. c only
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct answer as all the statements regarding the different types of nutrition are correct.

Multiple choice

Which of the following statements is/are correct?

  1. Green plants or primary consumers make up the first trophic level of the food chain.
  2. At the fourth level of the food chain are the decomposers, that is the organisms that break down dead or dying matter into nutrients.

  1. Only 1

  2. Only 2

  3. Both of these

  4. Neither of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The trophic level of an organism is the position it occupies in the food chain. Green plants make up the first trophic level and are known as primary producers. Plants are able to convert energy from the sun into food through a process known as photosynthesis. In the second trophic level, the primary consumers - known as herbivores - are animals and insects that obtain their energy solely by eating the green plants. The third trophic level is composed of the secondary consumers, flesh-eating or carnivorous animals that feed on herbivores. At the fourth level are the tertiary consumers, carnivores that feed on other carnivores. Finally, the fifth trophic level consists of the decomposers, organisms such as fungi and bacteria that break down dead or dying matter into nutrients that can be used again.

Multiple choice

Consider the following statements:

  1. Feeding on dead and decaying organisms is a parasitic mode of nutrition.
  2. Scorpions are omnivores.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement 1 is incorrect. Feeding on dead and decaying organisms is a saprophytic mode of nutrition. Statement 2 is also incorrect. Scorpions are carnivorous. They derive energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue.

Multiple choice

Consider the following statements:

  1. Androecium is a female part of plants.
  2. Heterotrophic mode of nutrition is a characteristic feature of the kingdom Animalia.

Which of the given statements is/are correct?

  1. Only 1

  2. Only 2

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statement 1 is incorrect. Androecium is a male part and gynoecium is a female part of plants. Statement 2 is correct. Heterotrophic mode of nutrition is one of a characterstic feature of kingdom Animalia.

Multiple choice

Find the mismatched pair(s).

  1. Saprophytic – Organisms that obtain their food from dead and decaying organic matter.
  2. Parasitic - Organism living on another organism for food usually causing it harm.
  3. Holozoic - Obtaining nutrients from other organisms or organic matter.
  4. Heterotrophic – Organisms that obtain their food from plants.

  1. Only 1

  2. Only 2 and 3

  3. Only 1 and 4

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All are correctly matched.

  1. Saprophytes obtain their food from dead and decaying organic matter.
  2. Parasites live on another organism for food usually causing it harm.
  3. Holozoic organisms obtain nutrients from other organisms or organic matter.
  4. Heterotrophic organisms obtain their food from plants.