Our Environment

i. Only 10 % of the available energy gets transferred to the next trophic level.

ii. In a given example if grasshopper has 4000 j energy then, only 10% of total energy from grasshopper will be is transferred to frog that is 400 j and snake will receive 40 J of energy.

As per 10 % law of energy transfer, if 100 j of energy is available at lion then deer should have 1000 j and grass will have 10,000 j of energy.

● Non-biodegradable are those waste which are not decomposed or degraded or broken down by microorganisms such as bacteria and fungi. Aluminium, plastics are examples of non-biodegradables.

● Empty packet of chips, empty plastic bottle of mineral water are non-biodegradable waste.

CFCs (Chlorofluorocarbons) are the group of chemical compounds which are mostly released from industries, refrigerators and air conditioners. These gases affects the ozone layer and are responsible for the depletion of ozone layer.

During photosynthesis, glucose (a type of carbohydrate) is formed by plants using solar energy. But plant stores glucose in the form of starch, a polysaccharide.

The phenomenon is ‘biomagnification’. It is the tendency of non-biodegradable substance such as pesticides to get accumulated as they move from one tropic level to the next.

Every ecosystem has abiotic (non-living) things) and biotic (living things and there is interaction between living and non-living things. In lake also there is interaction between abiotic components such as water, temperature, soil with biotic components such as plants and animals living in and around the lake.

● Every food chain begin with plants or any photosynthetic organisms because these are producers produce food for all other organisms in the food chain.

● Trophic levels in the food chains can’t be more than 4 or 5 because during energy transfer only 10% energy is transferred to the next level. Top consumer gets only small amount of energy. Hence, it will be difficult to sustain more than 5 trophic levels in a single food chain.

● The Ozone layer is a region mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometers above Earth. It absorbs most of the Sun's harmful ultraviolet radiation.

● CFCs (Chlorofluorocarbons) are the group of gases which are mostly released from industries, refrigerators and air conditioners. These gases cause depletion of ozone layer.

Chlorofluorocarbons (CFCs) released to the atmosphere through the use of aerosols containing CFCs and as leakages from refrigeration equipment. Other releases may occur from industry producing and using them and other products containing them. There are no any natural sources of CFCs to the environment.

Cause of concern:

● Releases of CFCs have serious environmental consequences. They can destroy the ozone layer, thus reducing the protection it offers the earth from the sun's harmful UV rays.

● CFCs also contribute to Global Warming (through "the Greenhouse Effect").

Snakes eat frogs. They are tertiary consumers in the given food chain and occupies fourth trophic level.

Microorganisms such as bacteria and fungi are decomposers. They decompose dead and decaying organic matter of plants and animals in the process of decomposition. In decomposition microorganisms’ breakdown dead and decaying matter and release of nutrients back into the environment.

The Suitable mechanism for wastewater management in the fertiliser industry are as follow:

● Fertiliser factories release effluents and harmful gases as the main waste.

● To control of gaseous pollutants, combustion equipment are used which can be oxidised the pollutants. Air pollutants, such as certain gases and vapour and inflammable compounds are controlled through the use of adsorption equipment.

● Effluents can be controlled by pre-treatment before discharge to municipal treatment systems. Waste water can be treated completely at the factory and either reused or discharged directly.

(a) Green plants contain cell organelles called chloroplast. Chloroplast contains green colour pigments called chlorophylls. Chlorophylls have ability to trap solar energy and this energy is used to fix carbon dioxide into food (glucose). Since green plants produce food, so they are called producers.

(b) The scientific term used for progressive accumulation of harmful chemicals at each trophic level of a food chain is “biological magnification”. It occurs when the number of chemicals and toxins increase and accumulate through the trophic levels of a food chain. Chemical substances from crop fields and industries are released into the environment, making their way toward food chains and food webs. Normally biological magnification doesn’t affect directly but exposure to these harmful chemicals may cause some long-term side effects.

● An aquarium is an artificial ecosystem and incomplete ecosystem compared to ponds. In an aquarium, organisms live in a very limited space and restricted environment. Uneaten food as well as the waste excreted by the organisms mix with the water and is left untreated due to the lack of decomposers. The waste materials thus accumulate in the water making it toxic. Hence an aquarium has to be cleaned after regular intervals.

● On the other hand, a pond or a lake ecosystem is a natural ecosystem covering a larger area. The waste produced in the lake or pond gets decomposed by microorganisms. This ensures a balance in the water body and keeps the water clean and thus does not require physical cleaning.

● Sun is the ultimate source of energy in an ecosystem. Energy always flows from sun to the producer through photosynthesis. Producers such as green plants make food for other organisms. From producers energy is transferred to different consumers. Thus, energy always flow from sun to producer and then to consumers.

● DDT is an insecticide and is non-biodegradable compound.

Once this insecticide sprayed in the environment, it stays for very long time and through food chain into the organisms.

According to the concept of biomagnification, the maximum accumulation of a non-biodegradable pollutant is maximum in the highest trophic level.

Hence, DDT gets accumulates at each trophic level and since, man is at the highest trophic level, there is maximum accumulation of DDT observed in them.

The following four eco-friendly activities we should practice in our daily life to keep environment clean and pollution free.

I. Those who are using vehicle for commuting, should use public transport or travel by car pooling. By doing this harmful emission from vehicle will be reduced.

II. We should carry either cloth or jute bag whenever we go for shopping try to avoid use of non-biodegradable plastic bags.

III. As far as possible, farmers or vegetable growers should use compost and vermicompost in their crop fields instead chemical fertilizers.

IV. Harvesting of rainwater and preventing wastage of resources.

V. Follow 3Rs approach, that are reduce wastage, recycle of materials and reuse of resources as far as possible.

● Biomagnification is a phenomenon in which certain harmful chemicals such as pesticides, fungicides get accumulated in the body of organisms in higher concentration through food chain.

● The organisms at highest trophic level, in them accumulation is the highest.

● Example: DDT shows biomagnification. It is an insecticide used to kill mosquitoes.

● DDT gets accumulated in the successive trophic levels. Zooplankton, small nekton, larger fish etc., anyone who eats these fish also have higher level of DDT than fish.

● DDT found in phytoplankton is 800 times more than that of water and zooplanktons have five times more than that of Phytoplanktons.

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In fish population, it is increased 40 times and 25 times more in fish eating birds.

(a)

(b) Indian government focusing on the use of jute or cloth carry bags due to the following aAdvantages:

● Jute is a biodegradable material, so jute bags can be degraded by decomposers. Secondly jute bags can be reused for longer time as compare to plastic bags.

● They do not pollute the environment. Hence, it eco-friendly.

● They are strong and more durable than plastic bags.

● They are capable of carrying more things.

(c) An artificial ecosystem is a system which is not self-sustaining and requires human interference in order to survive. The artificial ecosystem would not survive without human assistance. For examples Aquariums, crop field, manmade pond and garden. Artificial ecosystems consist of plants and species outside their natural habitat. Without humans, artificial ecosystems could not sustain itself. The plants and animals need help of humans to eat and survive.

(a) Ozone is a colourless gas and chemically is very active; it reacts readily with a many other substances. Ozone gas shield the Earth surface from the harmful UV-radiations from the sun protecting living things below.

(b) The living things in an ecosystem are called biotic components in the ecosystem are the living things. Living things include plants, animals, bacteria, fungi. In an ecosystem. Abiotic components are non-living things. These includes sunlight, temperature atmospheric gases water and soil. Abiotic and biotic components interact each other in an ecosystem.

(c) Plastic are non-biodegradable substance. It cannot be degraded by decomposers. It remains in the environment for longer time and would have hazardous impact if it persists in the environment for a long time.