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Full for of CFCs is chlorofluorocarbons, commonly known as Freon, CFCs are used in in air-conditioning, refrigeration, blowing agents in foams, insulations and packing materials, propellants in aerosol cans.

The level of organization in nature are Species 

→ Population → biotic community 

→ ecosystem → biosphere.

Food chain shows that how the energy is passed from one organism to another.

The basic laws of ecology are. 

1. We can never continue to do any thing in nature. 

2. In nature every thing is connected with everything else.

The energy flow through different steps in the food chain is unidirectional. This means that energy captured by autotrophs does not revert back to the solar input and it passes to the herbivores, i.e. it moves progressively through various trophic levels. Thus, energy flow from the sun through producers to consumers is in single direction only.

Land, air, water, sunlight, humidity etc. are the physical or abiotic factors in a biosphere.

The Scientific studies which enable us to understand the totality and pattern of the relations between organisms and their environment is called ecology.

The high energy of UV radiations breakdown some molecules of O₂ into atoms of oxygen. One atom of oxygen binds to one molecule of O to form O₃ . Ozone prevents UV rays to reach earth surface.

O₂ + U.V → O + O

O_{2 + O} → O₃(Ozone)

Example : Chlorofluorocarbons

Ultra violet radiation.

Hydrosphere, atmosphere and lithosphere of the earth together constitute the biosphere. It is the sun total of the all organisms and their places of living.

The Surface or crust of the earth is called lithosphere.

When the earth was formed about 4.8 billions of years ago. Earth was a hot revolving ball of gas. The extremely high temperature and the dry climate of the earliest earth would have made it impossible for the life to appear and exist. The first multi cellular organisms appeared about 1.4 billion years ago. 

These organisms and the other forms of life which evolved from them could survive when the condition on earth began to stabilize gradually.

1. Pollution levels increase during monsoon season in water bodies. 

2. During monsoon season heavy rainfall occurs. 

3. The rain water brings residues of agrochemicals, fertilizers and different types of organic substances, municipal and domestic sewage. 

4. Hence pollution levels increase in monsoon season.

Atmosphere of the earth at its beginning was rich in carbon dioxide and oxygen content was very less. As photosynthetic algae appeared on earth oxygen concentration increased resulting in a shift from reducing type of atmosphere to an oxidizing type Gradually atmosphere reached its present composition. Which is ideally suited for humans and other forms of life.

Edulabad water reservoir is located in urban areas of Ranga Reddy district of Telangana.

(C) Crop rotation

1. Water requires considerable amount of energy to get heated up and also to get converted from a liquid state into a gaseous state. On a very hot day, water bodies help maintain atmosphere temperature cool by absorbing heat from the sun. When the sun” sets. The heat which water has absorbed is returned to the atmosphere, as water evaporates. Such a regulation is crucial for the survival of living organisms. 

2. Water has a high resistance to sudden changes in temperature and this feature makes water an excellent habitat for most organisms. 

3. At 4° water can expand on cooling or heating this feature ensures that all the, water in a water body will be close to 0° c before any freezing can occur. 

4. The high surface tension of water and its tendency to expand on freezing helps in weathering of rocks. 1 ending to soil formation.

Cyprinus carpio (common scale carp) is the fish species grown in Edulabad water reservoir.

The bioaccumulation of heavy metals in tissues of fish particularly in liver, kidney and gills were analysed and found their presence.

A) Renal damage

Fish are considered to be the bioindicators of metal contamination in environmental monitoring because fish species are strongly respond to stress conditions.

D) Bio magnification

(D) All are correct

Answer is (A) Correct

The basic unit of study in environment is Organism.

(d) All of the above.

Advantages of cloth bags over plastic bags during shopping are as follows 

• They can carry more weight than plastic bags 
• They are bio-degradable 
• They can be reused. 
• They do not cause environment pollution.

Plastic is a non-biodegradable substance.

Hence a plastic bag will persist in the environment and lead to several environmental problems.

It would be better to use paper bags or cloth bags instead of polythene bags.

Plastic bags are non-biodegradable wastes, they are not degraded, they begin to stink, emitting foul gases, spoil the beauty of places and contaminate soil, water and air with toxins.

Cloth bags are used instead of plastic bags because they are stronger more durable and washable.

Advantages of cloth bag :

(i) Cloth bags are stronger and more durable as compared to plastic bags.

(ii) They are washable.

(iii) They can be used repeatedly.

(iv) Cloth bags do not pollute environment.

(v) They are made of biodegradable material which can be recycled.

(i) Disposing of biodegradable wastes in biogas plants so that it can help in the preparation of biogas and manure.
(ii) Solid wastes should be buried in urban areas as landfills.
(iii) Some solid wastes (plastic, paper and metals) should be recycled.
(iv) Large amount of waste must be burnt at high temperature (incineration).

The answer is (b) Green plants get their food from organic compounds

• Green plants produce their food by harnessing solar energy. 
• Solar energy is used to prepare carbohydrate with the help of CO₂ and water which are in-organic substances.

C) primary consumer to secondary consumer

Incineration means reducing to ashes. It is used to destroy the household waste, chemical waste and biological waste.

(b) Plastic bags

(b) Planting of trees

The series of organisms taking part at various biotic levels form a food chain. Food chains describe the feeding relationship between the organisms of an ecosystem. The flow of energy from one species to another at various biotic levels forms a food chain. A food chain always starts with producers.

The successive levels in the food chains of a community are called as trophic levels. From autotrophs the energy goes to the heterotrophs and decomposers. When one form of energy is change to another, some energy is lost to the environment in forms which cannot be used again. Some common food chains are mentioned below.

Plants →Deer→ Lion

Plants →Grasshopper →Frog →Snake→ Hawk

Algae →Small animal →Small fish→ Big fish →Bird

Food chains generally consist of only three or four steps. The loss of energy at each step is so great that very little usable energy remains after four trophic levels. There are generally a greater number of individuals at the lower trophic levels of an ecosystem; the greatest number is of the producers.

The length and complexity of food chains vary greatly. Each organism is generally eaten by two or more other kinds of organisms which in turn are eaten by several other organisms. The relationship can be shown as a series of branching lines called a food web. Food web is a web of cross-linked food chains.

There is a flow of energy in the form of food within an ecosystem. The flow of energy is unidirectional. The energy that is captured by the autotrophs does not revert back to the solar input and the energy which passes to the herbivores does not come back to autotrophs. Also, some harmful chemicals enter our bodies through the food chain. One of the reasons is the use of several pesticides and other chemicals to protect the crops from diseases and pests through which they enter the food chain.

All organisms such as plants, animals, microorganisms and human beings as well as the physical surroundings interact with each other and maintain a balance in nature.

The ecosystem is a community of organisms and their physical environment interacting with each other as an ecological unit, involving the flow of energy. An ecosystem consists of biotic components including living organisms and abiotic components, the physical factors like temperature, rainfall, wind, soil and minerals.

An ecosystem can be natural or artificial. Ponds, forests and lakes are natural ecosystems while garden and crop fields are human made or artificial ecosystems. In both the ecosystems all living organisms interact with each other and their growth, reproduction and other activities are affected by the abiotic components of ecosystem.

Organisms in the ecosystem can be categorised into producers, consumers and decomposers according to the manner in which they obtain their substance from the environment. 

Producers are the organisms that produce their own food without the help of any other organism. These are also known as autotrophs. They make their food from inorganic substances through a process called photosynthesis. Autotrophs are green plants, phytoplankton and blue green algae.

Consumers are the organisms which cannot produce food but depend directly or indirectly on producers for the same. These are also known as heterotrophs. Consumers can be classified into herbivores, carnivores, omnivores and parasites. Eg: Humans, Snake, Eagle Decomposers are the organisms which feed on dead and decaying matter. They break down the complex organic substances into simple inorganic substances that go into the soil and are sued up once more by the plants. Eg: Bacteria and fungi.

(i) Biomagnification is maximum in fourth trophic level i.e., fish. 

(ii) (a) Caused by the use of several pesticides and chemicals for crop protection and storage. 

(b) It harms the trophic level and causes toxicity and death. 

(c) It can be prevented by minimizing the use of chemicals in food productivity.

The tendency of pollutants to concentrate as they move from one tropic level to the next is known as Biomagnification.

C) Both a and b are true

The ratio between energy flows at different tropic levels among the food chain expressed as percentage is called ecological efficiency.

The major sources of pollution are agricultural runoff containing residues of several agrochemicals, fertilizers, fish tank discharges, industrial effluents containing chemical residues and different types of organic substances, municipal and domestic sewage.

A) Bird sanctuary

The process of entering of pollutants in a food chain is known as Bioaccumulation.

The ratio between energy flows at different tropic levels along the food chain expressed as a percentage is called “Ecological efficiency”.

The objective of operation Kolleru by the ministry of environment and forest, Government of India is to bring back the ecological balance of Kolleru lake which is a gift of nature.

The pyramid of biomass represents the relationship that exists between the quantity of living matter at different trophic levels.

Indiscriminate use of pesticides may result in the degradation of the environment. For example, DDT is an organic pesticide which is used to kill pests in crop fields. When it is used in large quantity it can be passed along the food chain from crops to man or other animals and birds and can harm them.

(b) Top Carnivores, Carnivores, Herbivores, Producers