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

An organism derives its nutrients from another organism in

  1. Holozoic nutrition

  2. Parasitic nutrition

  3. Saprotrophic nutrition

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

Parasitic nutrition is a mode of nutrition where organism (known as a parasite) lives on the body surface or inside the body of another type of organism and obtains nutrition directly from the body of the other organism (known as a host).

Multiple choice

The turnover of biomass at each trophic level is represented by

  1. Pyramid of numbers

  2. Pyramid of productivity

  3. Pyramid of biomass

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

An ecological pyramid of productivity is often more useful, showing the production or turnover of biomass at each trophic level. Instead of showing a single snapshot in time, productivity pyramids show the flow of energy through the food chain. Typical units would be grams per meter2  per year or calories per meter2  per year. As with the others, this graph begins with producers at the bottom and places higher trophic levels on top.

Multiple choice

Which one of the following statements is not correct?

  1. The energy levels within a food chain are called levels

  2. In deep oceans, primary production is almost nil

  3. the primary consumes are called autotrophs

  4. The decomposers are called saprotrophs
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The incorrect statement is (c) because primary consumers are heterotrophs, not autotrophs. Autotrophs (like plants) produce their own food through photosynthesis, while primary consumers are organisms that feed on autotrophs. The other statements are generally accurate regarding ecological concepts.

Multiple choice

The correct path of energy flow in an ecosystem is

  1. producers – carnivores – herbivores – decomposers

  2. producers – herbivores – carnivores – decomposers

  3. herbivores – carnivores – producers – decomposers

  4. herbivores – producers – carnivores – decomposers
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The correct path of energy flow in an ecosystem is producers – herbivores – carnivores – decomposers.

Multiple choice

Nepenthes eats insects, only to get

  1. Phosphorus

  2. Carbon

  3. Nitrogen

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

Nepenthes (pitcher plant) grows in nitrogen-deficient soils like bogs. It has evolved carnivory to supplement nitrogen intake by trapping and digesting insects. Carbon is obtained from photosynthesis, while sulfur and phosphorus are typically available in the soil.

Multiple choice

Name the mode of nutrition in kingdom Plantae.

  1. Autotrophic

  2. Saprophytic

  3. Parasitic

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

Kingdom Plantae is characterized by autotrophic mode of nutrition - they synthesize their own food through photosynthesis using chlorophyll and sunlight. Saprophytic and parasitic nutrition are more common in fungi. Holozoic nutrition involves ingesting solid food, which is characteristic of animals.

Multiple choice

What is the mode of nutrition in mushroom?

  1. Autotrophic

  2. Symbiotic

  3. Saprophytic

  4. Parasitic

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

Mushrooms are fungi, and fungi have a saprophytic mode of nutrition. Saprophytes obtain nutrients by absorbing dissolved organic matter from dead and decaying organisms. They secrete digestive enzymes into their environment and then absorb the broken-down nutrients. Unlike autotrophs (plants, some bacteria) that produce their own food, or parasites that obtain nutrients from living hosts, mushrooms (fungi) are decomposers that feed on dead organic matter.

Multiple choice

Plants differ from animals in having

  1. locomotion

  2. metabolism

  3. localised growth

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

Plants exhibit localized or indeterminate growth through meristems (apical and lateral), allowing continuous growth throughout their lifespan. Animals show determinate growth with fixed body plans after maturity, though both possess metabolism and catabolism.

Multiple choice

What is the mode of nutrition of scavengers?

  1. They feed on dead or injured animals

  2. They eat both plants and meat

  3. They eat plants

  4. They eat meat

  5. They eat insects
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Scavengers are animals that feed on dead or injured animals.

Multiple choice

Animals consume nitrogen mainly in the form of

  1. dissolved in water

  2. proteins

  3. salts

  4. gas during inspiration
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Animals obtain nitrogen primarily through consuming proteins (which contain nitrogen in amino acid structures). Plants synthesize proteins from soil nitrates, and animals acquire nitrogen by eating plants or other animals.