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 correctly defines saprophytic organism?

  1. Organism that feeds on green plants

  2. Organism that feeds on dead and decaying matter

  3. Organism that feeds on fruits only

  4. Organism that feeds on insects and worms
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Saprophytic organisms obtain nutrition by feeding on dead and decaying organic matter. They play a crucial role in decomposition and nutrient cycling in ecosystems. Option B correctly identifies this mode of nutrition, while other options describe different feeding strategies (herbivory, frugivory, carnivory).

Multiple choice

Keystone species are those which

  1. are connected to a disproportionately large number of other species in the food web
  2. have lower levels of biomass in the trophic pyramid relative to the importance of their role

  1. Only 1

  2. Only 2

  3. Both 1 and 2

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

A keystone species is a species that is connected to a disproportionately large number of other species in the food web. Keystone species have lower levels of biomass in the trophic pyramid relative to the importance of their role. 

Multiple choice

Why can't animals make food from carbon dioxide, water and minerals as plants do?

  1. Because animals move from one place to another.

  2. Because animals eat flesh and plants to live.

  3. Because animals don't have chloroplast like plants.

  4. Because animals cannot take in water and carbon dioxide.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, it is correct. Plants have chloroplasts in which a green pigment, chlorophyll is present. It helps plants to capture the energy of sunlight.

Multiple choice

Which of the following options is not an adaptation of a polar bear to the severe conditions of polar regions?

  1. It has two thick layers of fur.

  2. It has long curved and sharp claws.

  3. It has a long tail.

  4. It has a thick layer of fat under its skin.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, it is not the adaptation of polar bear. The tail of a polar bear is not long rather it has a short tail. It has a stubby short tail which helps it to keep its body warm.

Multiple choice

Which of the following statements is appropriate for herbivores?

  1. Herbivores are secondary producers.

  2. Herbivores are primary consumers.

  3. Herbivores are primary producers and secondary consumers.

  4. Herbivores are primary producers.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Herbivores are primary consumers because they eat plants (producers). They are not producers themselves - they cannot photosynthesize.

Multiple choice

The trophic levels represent the

  1. steps in a community

  2. steps in a food chain

  3. steps in an ecosystem

  4. steps in a biosphere
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The trophic levels represent the steps in a food chain.

Multiple choice

Select the correct order of organisms in a food chain from the following data?

  1. Human, duck, fish, algae

  2. Algae, fish, duck, human

  3. Algae, duck, fish, human

  4. fish, duck, algae, human
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The correct order follows energy flow: Algae (producer) → Fish (primary consumer) → Duck (secondary consumer) → Human (tertiary consumer). Energy moves up through each trophic level.

Multiple choice

Herbivores are found in which trophic level?

  1. First

  2. Second

  3. Third

  4. Fourth
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Herbivores occupy the second trophic level because they eat plants from the first trophic level (producers). They are primary consumers in the food chain.

Multiple choice

Which of the following statements is true?

  1. Deer is a carnivore.

  2. Lion is an autotrophic animal.

  3. Predators are usually lesser in number than their preys.

  4. Each species is limited in its total biomass by its trophic level.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Each trophic level has limited total biomass because energy is lost at each transfer (10% rule). This means higher trophic levels can support less total biomass. Deer are herbivores, lions are heterotrophs not autotrophs, and predators typically have fewer numbers than prey (not greater).