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 botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Organisms that feed upon decaying matter are called as

  1. Heterotrophs

  2. Saprophytes

  3. Myxophytes

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

Depending upon the mode of nutrition the organisms are classified as autotroph and heterotroph. 

The autotrophs can synthesize their own food material from inorganic substances. 
The heterotrophs cannot synthesize their own food material. They have to obtain their food from other organisms. 
Saprophytes are one of the types heterotrophs. They are organisms which derive their food from dead and decayed organisms. 
Therefore, the correct answer is option B.

Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Which one of the following has a saprophytic mode of nutrition?

  1. Roundworm

  2. Leech

  3. Mushroom

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

The mode of nutrition in which non-green plants take in nutrients in solution form from dead and decaying matter is called saprophytic or saprotrophic nutrition. Fungi, mushrooms, yeast and many bacteria are examples of saprophytes. Roundworms, leeches and lice are parasites, i.e., they live on or in another organism and get their nutrition from them.

Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

The organisms obtain nutrients from dead and decaying organic matter from which mode?

  1. Parasite

  2. Autotroph

  3. Saprophytes

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

Holozoic modes of nutrition is a method of nutrition that involves the ingestion of liquid or solid organic material, digestion, absorption and assimilation of it to utilize it. For example, amoeba. 

Saprophytes are the animals which feed on dead and decaying animals. For example, moulds, mushroom etc. 
Parasitic mode of nutrition is that in which organism feeds on a living organism (host). For example, leach, flatworm,plain worms etc. 
Autotroph is an organism that manufactures its own food from inorganic substances, such as carbon dioxide and ammonia. Most autotrophs, such as green plants, certain algae, and photosynthetic bacteria, use light for energy. 
Therefore, the correct answer is option C.

Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Few plants cannot synthesise food on their own and depend upon other plants and small animals. They are called as heterotrophic plants. These heterotrophs are classified in

  1. Thallophytes and bryophytes

  2. Saprophytes and parasites

  3. Xerophytes and hydrophytes

  4. Saprophytes and pteridophytes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Parasite are the organism, which depends upon other organism for its nourishment and growth, is known as parasite. It has intracellular digestion. It causes harm to the organism. 

Saprophyte is an organism, which grows on dead and decaying material for its growth, is known as saprophyte. It shows extracellular digestion. It does not depend on living host. 
Thallophytes, bryophytes, xerophytes, pteridophytes and hydrophytes are autotrophs. 
Therefore, the correct answer is option B.

Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Bread mould gets its food

  1. Through photosynthesis

  2. Non living matter

  3. By eating herbivorous animals

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bread mold (Rhizopus stolonifer) is a widely distributed thread-like mucoralean mold. Commonly found on bread surfaces, it takes food and nutrients from the bread and causes damage to the surface where it lives. Asexual spores are formed within pinhead-like sporangia, which break to release the spores when mature. Germination of these spores forms the haploid hyphae of a new mycelium. R. stolonifer grows rapidly at temperatures between 15 and 30°C. 

Therefore, the correct answer is option B.

Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Which of the following plants shows the saprotrophic mode of nutrition?

  1. Dodder

  2. Venus fly trap

  3. Nepenthes

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

While mushrooms are actually fungi rather than plants, they exhibit saprotrophic nutrition by obtaining nutrients from dead and decaying organic matter in soil. Unlike the other options which are parasitic or carnivorous plants, mushrooms are decomposers.

Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Which of the following is true about Saprophytes?

  1. They trap insects to meet their nitrogen requirement.

  2. They live on decaying organic matter.

  3. They share their food and shelter.

  4. Saprophytes contain chlorophyll.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
A saprophyte or saprotroph is an organism which gets its energy from dead and decaying organic matter. This may be decaying pieces of plants or animals. This means that saprophytes are heterotrophs. They are consumers in the food chain. This is the typical life-style of fungi.

So, the correct answer is 'They live on decaying organic matter.'.
Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Which organism transforms complex organic compounds back into simple inorganic compound?

  1. Saprotrophs

  2. Consumers

  3. Producers

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

Saprotrophs, such as bacteria and fungi, are decomposers that break down organic matter from dead organisms into simpler inorganic substances. This process recycles nutrients back into the ecosystem.

Multiple choice botany know the plant world closely nutrition and its types types of nutrition in plants different modes of nutrition in plants

Nepenthes belongs to the category of

  1. Primary consumer

  2. Producer

  3. Secondary consumer

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

Nepenthes belongs to the category of producer and secondary consumer. It is also called as topical pitcher plant. It belongs to category of producer as it can synthesize its own food using solar energy. It belongs to secondary consumer because it is a carnivorous plant. It  preys the insects and derives nitrogen from it. Thus, the correct answer is 'Both B and C.'

Multiple choice botany through the alimentary canal nutrition and its types types of nutrition in plants different modes of nutrition in plants

Find the one that is not involved in symbiotic nutrition.

  1. Lichen

  2. Mycorrhiza

  3. Mucor

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

Mucor is fungi that are found in soil, digestive systems etc.

Rest three are involved in symbiosis. Lichens are the symbiotic association between algae and fungi where the algae provide nutrition and fungi provides a place to live and protection.
Mycorrhiza is the symbiotic association in between fungi and roots of higher plants. eg. orchids and pine.
Rhizobium is a nitrogen-fixing bacteria that is in association with the root nodules of the legumes plants.
So, the correct option is 'Mucor'

Multiple choice zoology ecosystems decomposition in ecosystem ecosystem productivity and decomposition producers, consumers and decomposers

The process of breakdown of detritus by detrivores is

  1. Mineralisation

  2. Fragmentation

  3. Leaching

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

Decomposition is the process of breaking of complex organic matter into simpler inorganic matter. There are five steps of decomposition. These are fragmentation, leaching, catabolism, humification and mineralization. Fragmentation is the process of breaking of detritus into small pieces by detrivores such as earthworm. Leaching is the process of releasing nutrients in the water and seeping into the soil. Catabolism is the process of breaking down of complex molecules into the simpler molecules. Humification is the process of formation of dark colored substance humus on the soil. It undergoes microbial action at a slow rate. Mineralization is the process of degradation of the hummus to release inorganic nutrients.

Thus, the correct answer is 'Fragmentation.'