Class 11 Environment Chapter 2 Ecological Concepts

Class 11 Environment Chapter 2 Ecological Concepts The answer to each chapter is provided in the list so that you can easily browse through different chapters Assam Board HS 1st Year Environmental Studies Chapter 2 Ecological Concepts Question Answer.

Class 11 Environment Chapter 2 Ecological Concepts

Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given Assam Board Class 11 Environment Chapter 2 Ecological Concepts Notes for All Subjects, You can practice these here.


1. Give an account of the biotic and abiotic components of biosphere.

Ans: Biosphere has two main components: 

(i) Abiotic or non-living components

(ii) Biotic or living components.

(i) Abiotic Components: The abiotic components of the biosphere are water, gases and mineral elements. The factors like sunlight, temper n food from simple inorganic substances like carbon dioxide and water, in the presence of light.

Consumers: The organisms which consume food prepared by the producers are called consumers.

Decomposers: The micro-organisms which break down the complex organic compounds of the dead remains of plant and animals and their products like faeces, urine etc. into simpler substances are called decomposers.

2. Diagrammatically show the structure of the atmosphere. 

Ans: Atmosphere is formed of the gaseous cover which envelops the hydrosphere and the lithosphere. On the basis of temperature the atmosphere can be roughly divided into four zones.

They are:

(i) Troposphere

(ii) Stratosphere

(iii) Mesosphere

(iv) Ionosphere.

(i) Troposphere: The basal part of the atmosphere which is about 20 km above the earth’s surface is known as troposphere. Cloud formation, thundering, lightning etc. take place in this zone. Air temperature gradually decreases with increasing height. This is the most important zone of the atmosphere for organisms.

(ii) Stratosphere: This zone extends upto 30 km in height. The temperature in this zone increases upto 90oC. The increase in temperature in this zone is due to the formation of ozone under the influence of ultraviolet component of sunlight.

(iii) Mesosphere: Mesosphere is about 40 km in height from the stratosphere. Temperature in this zone again goes down upto 800.

(iv) Ionosphere: The rest of the atmosphere above the mesosphere upto a height of above 400 km above the earth’s surface is ionosphere. Most of the gaseous components which become ionized under the influence of the radiant energy, remain as ions in this zone. The lower most region of ionosphere is called thermosphere. It is 85 km above the surface of the earth. The layer above ionosphere is called exosphere.

3. Explain the relationship amongst the producers, consumen and the decomposers.

Ans: The relationship amongst the producers, consumers and the decomposers is as follows:

The producers are the green plants which trap solar energy and conven it to potential energy. All the consumers like animals and rion-green plants directly or indirectly depend upon the plants for energy and the decomposers are non-green microbes which break down the complex organic compounds of the dead remains of plant and animals and the products like faeces, urine etc. into simpler substances.

4. Distinguish between:

(a) Phagotrophs and Saprotrophs.

Ans: The organisms which consume other organisms are known as phagotrophs and the micro-organisms which feed on dead organic matters are known as saprotrophs.

(b) Autotrophs and Heterotrophs.

Ans: The organisms which can prepare their own food from simple inorganic substances like carbon dioxide and water, in the presence of light are known as autotrophs. For e.g.-Green plants.

All the consumers which are dependent on autotrophs for their food are known as heterotrophs. For e.g.-Lion, tiger, etc,

(c) Herbivore and Carnivore.

Ans: The organisms which derive their food directly from plants or producers are called herbivores. For e.g. cow, buffalo, goat, deer etc. They are also known as primary consumers or first order consumers.

The organisms which feed on herbivores are called secondary consumers or second order consumers or carnivores. For e g. lion, tiger, snake, hawks and frog etc.

(d) Micro-consumers and Macroconsumers.

And: The micro-consumers are also called the saprobes or saprophytes. They constitute a sort of heterotrophic organisms that break down the complex compounds of dead protoplasm, absorb some of the decomposition products, and release simple substance for utilising by the producers. For eg.-bacteria and fungi.

Mitro-consumers are also known as phagotrophs. They constitute a sort of heterotrophic organisms, chiefly animals that ingest other organisms or particulate organic mater. For eg.-lion, tiger etc.

5. Write short notes on :

(a) Homeostasis.

Ans: The ecosystem, by itself, tries to resist the change and maintain itself in equilibrium with the environment owing to a property which is known as homeostasis. Homeostasis is the inherent property of all living systems to resist change. It is capable of self-maintenance and self regulation.

(b) Biomes

Ans: The natural ecological groupings of plants and animals made on the basis of climates are called biomes. The existence of plants and animals in an area is determined by the climatic conditions of the area. Same type of plants and animals appear together in similar climatic zones, Biomes may also be termed as major ecosystems of the earth. The major biomes of the world are Tundra, Northern Conifer forest or Taiga, Temperate deciduous forest, Tropical rain forest, Chapparal, Tropical Savannah, Grassland, Desert.

(c) Food chain.

Ans: A food chain is simply a series of different kinds of organisms through which food energy flows in an ecosystem. All the food chains begin with a producer i.e. green plants which is the origin of all food There is a sequence in which one organism cats up the other organism for survival. For example, in grassland ecosystem the grass is eaten up by animals like deer and the deer in turn is consumed by a lion.

One of the examples of food chain is:

Grass → Insects → Frog → Snakes → Hawk

(Producer) (Herbivore) (Carnivore) (Large Carnivore) (Top Carnivore)

(d) Food web.

Ans: The linear arrangement of producers and consumers in an ecosystem does not reflect the interrelationship amongst the various organisms of an ecosystem. In fact, many animals may act as consumers of first, second or third order. The inter connected food-chains operating in an ecosystem which establish a network of relationships between various species, is called food web.

(e) Trophic level.

Ans: The producer-consumer arrangement in an ecosystem is one kind of structure called trophic structure and each food level is known as trophic level. The amount of living materials in the different trophic levels or in a component population is known as the standing crop, irrespective of plants and animals.

Different trophic levels of an ecosystem are:

(i) The plants are producers and constitute the first trophic level

(ii) Herbivores which fed upon the plants constitute the second trophic level.

(iii) Carnivores which feed upon the herbivores are called the third trophic level.

(iv) Large carnivores or top carnivores that feed upon the small carnivores constitute the fourth trophic level.

6. Write about the various components of ecosystem and their functions.

Ans: An ecosystem may be defined as a self sustained community of plants and animals existing in its own environment.

There are two components of ecosystem. These are as follows: 

(a) Biotic Components: The biotic components of ecosystem include producer, consumers and decomposers.

Producer means the green plants and certain photosynthetic or chemosynthetic bacteria which produce food for all other organism. These can convert the Light energy of sun into potential chemical energy in the form of organic compounds, needed plants for their own growth and development.

Consumers refers to those organisms which get their from other organism and they are directly or indirectly depends upon the producer organisms. Consumers are consume the materials built up by the producers. There are three type of consumer. These are primary, secondary and tertiary consumers. Primary consumers feed on tree leaves. Ant flies, beetles, bugs, spiclers, elephants, deer, squirrel, mongoose etc are primary consumers.Secondary consumers feed on herbivores. Snakes, hirds, lizards, fox etc are considered as secondary consumer. Tertiary consumers are the top carnivores who eat upon consumers carnivores. Lion, tiger etc are tertiary type of consumers.

Decomposers are mostly parasitic and saprophytic which refers to the organism which derive their nutrition by breaking down the complex organic molecules into simpler organic compounds. Various bacteria and fungi are considered as decomposers.

(b) Abiotic Components: The non-living things which influence on the ecosystem is called abiotic components to determine the functioning of ecosystem are also called abiotic factor. Air, water, minerals, soil, light, temperature, salts, wind, topography, wave action, salinity and water logging etc.are abiotic components.

The ecosystem has many functions. The different function of an ecosystem are as follows –

(a) Ecosystem circulate between leaving and non-leaving organism. 

(b) In ecosystem flow of energy is consumed by autotrophs in the time of their respiration growth and any other metabolic reaction.

(c) Ecosystem exchange biotic and abiotic materials. in an ecosystem by dimensional and highly complex interrelation different components linked together.

(d) Ecosystem adjust a functional balance among various components.

(e) Ecosystem is achieved by a number of limitations, which is called cybernetics.

7. Write the causes of ecological succession and its basic types. 

Ans: A progressive organization of a biological community as a new plants and animals species come into an area and alter the environmental conditions is called ecological succession.

Ecological succession is of two types. These are as follows:

(i) Primary succession: When plants and animals colonize a previously desolate area then primary succession takes place, such as sand dune, new volcanic island, bare rock, or recently glaciated ground. Everything including the soil bacteria, insects, plants, and animals must come from nearby habitats in these situations.

(ii) Secondary Succession: In areas where communities have become established before an event then secondary succession occur, such as fire, landslide, flood, hurricane, field-clearing disturbs them.

8. What do you mean by food chain.

Ans: Food chain and food web: Food chain means the transfer of food energy from the producers, through a series or organsm with repeated eating and being eaten. In the food chain some organisms are omnivores as well as the carnivores at their lower level. In any food chain, energy flows from primary producers to primary consumers, from primary consumers to secondary consumers, from secondary consumers to tertiary consumers and so on.

9. What is meant by energy flow in ecosystem? Explain it with an example.

Ans: The energy from the sunlight is converted by the plants themselves into growing new plants materias. Leaves of trees, flowers, fruits, trunks brunches, roots etc of plants are the plants materials which formed through sunlight. Because the energy cerelle is based on the flow of energy through the ecosystem. Plants are known as producer in the ecosystem because plants can grow by conserving the sun’s energy into their tissues directly. Different plants and animals are linked to one another through food chain. Each plants or animals can be linked to several plants or animals. Those interlinked chains can be depicted as food web.

In the ecosystem the energy can be depicted in the form of a energy pyramid. It also known as food pyramid which has a large base of producer or plants. These are two types of consumers. One is first order consumers and the second one is second order consumers. The pyramid has a narrower middle section that depicts the number and biomass of herbivorous animals are first order consumers and the apex depicts the small biomass of carnivorous animals are the second order consumers. The materials are returned to the soil when plants and animals are die. Plants can absorb the nutrients through their roots..

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