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

In natural ecosystem, decomposers include

  1. only bacteria and fungi

  2. only microscopic animals

  3. the above two types organism plus macroscopic animals

  4. both (1) and (2)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Decomposers are organisms that break down dead organic matter. Bacteria and fungi are the primary decomposers in an ecosystem.

Multiple choice

Nepenthes is a

  1. primary producer

  2. consumer

  3. primary producer and consumer

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nepenthes (pitcher plants) photosynthesize like other plants, making them primary producers. However, they also trap and digest insects, functioning as consumers. This dual role is rare among plants.

Multiple choice

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

  1. commensales

  2. herbivores

  3. fauna and flora

  4. planktons
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Plankton is the collective term for microscopic organisms floating in aquatic environments. It includes both phytoplankton (plant-like) and zooplankton (animal-like), making it the correct answer. The other options are incorrect: commensales describes a symbiotic relationship, herbivores are plant-eating animals, and fauna and flora refers to larger animals and plants rather than microscopic organisms.

Multiple choice

The first link of food chain is green plants because

  1. they are widely distributed

  2. they are firmly fixed to soil

  3. they alone have the capacity to fix the atmospheric CO2 in the presence of sun light

  4. there are more herbivorous animals than the carnivorous
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Green plants form the first link of food chains because they are the only organisms capable of photosynthesis - converting atmospheric CO2 and sunlight into organic matter. This unique ability makes them the primary producers that support all other trophic levels. The other options (distribution, fixation to soil, herbivore populations) are not fundamental reasons for their position.

Multiple choice

A food chain consists of

  1. producers and primary consumers

  2. producers, herbivores and carnivores

  3. producer, consumers and decomposers

  4. producers, carnivores and decomposers
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A complete food chain includes all three essential components: producers (plants), consumers (herbivores and carnivores), and decomposers (bacteria and fungi). Decomposers are crucial because they break down dead organisms and recycle nutrients back to the soil, completing the cycle.

Multiple choice

Carnivores are

  1. usually primary consumers

  2. usually secondary consumers

  3. usually secondary or tertiary consumers

  4. usually decomposers rather than consumers
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Carnivores typically occupy secondary or tertiary consumer positions because they eat other animals. Secondary carnivores eat herbivores (primary consumers), while tertiary carnivores eat secondary carnivores. This positioning depends on the specific ecosystem and food chain complexity.

Multiple choice

A structural feeding hierarchy, whereby energy in the form of food is passed from an organism in a lower trophic level to one in a higher level, is called�

  1. Food supply

  2. Food crop

  3. Food chain

  4. All of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A food chain is the structural feeding hierarchy showing how energy flows from organisms at lower trophic levels (producers) to higher trophic levels (consumers). Each transfer represents energy passing through the ecosystem in a linear sequence.

Multiple choice

Which kind of organisms act as decomposers?

  1. Bacteria

  2. Vultures

  3. Tape worms

  4. Kites
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Decomposers are the micro-organisms which act on the dead remains and waste products of animals and plants. They breakdown the complex substances into simpler ones that mix into the soil and are used up by the plants.

Multiple choice

Which of the following statements is false about heterotrophic nutrition?

  1. In this process, no sunlight is required.

  2. In this process, no pigment is required.

  3. Bacteria show this process of nutrition.

  4. It is caused by unsynthesised food.

  5. It can occur in the presence of chlorophyll.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Heterotrophic nutrition does not take place in the presence of sunlight or chlorophyll.

Multiple choice

What is the meaning of nutrient regulation?

  1. Recycling of nutrients

  2. Storage of nutrients

  3. Maintaining diversity of organisms

  4. Consumption of resources

  5. Options (1) and (2)
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

These options are correct.

Multiple choice

Which two adaptations in a polar bear helps it to catch prey for food?

  1. Fatty, skin and thick fur

  2. Strong sense of smell and white fur

  3. White fur and fatty skin

  4. Thick and white fur
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Polar bears have a strong sense of smell and their bodies are covered with white fur. These features help them to locate and catch their prey easily without letting it escape.