Explore topic-wise InterviewSolutions in .

Bacteria and fungi breakdown the dead remains and waste products of organisms. These micro organisms are called the decomposers as they breakdown the complex organic substances into simple inorganic substances that go into the soil and are used up once more by the plants. 

Two advantages of decomposers to the environment are as follows: 

• Decomposers feed, on the dead bodies of plants and animals. They return the simple components to soil and help in making the steady state of ecosystem by recycling of nutrients. They, therefore, create a balance in the environment. 
• They also act as scavengers or cleansing agents of the atmosphere

Decomposers, scavengers

United Nations Environment Programme.

(a) Grass → Deer → Lion

O₃ is the formula of ozone.

(a) It is deadly poisonous

3 atoms of oxygen are there in ozone.

A natural forest is terrestrial ecosystem.

(d) Lizard and hawk.

The consumers are herbivores, carnivores, omnivores, parasites, saprophytes and decomposers.

The energy from the sun flows into autotrophs and it passes to herbivores and then to carnivores. The energy does not revert from autotrophs to the solar input or from herbivores back to autotrophs. Hence the flow is unidirectional.

Biodegradable: These substances can be broken down by the action of saprotrophs and other agents, e.g., paper, cloth. 

Non biodegradable: These substances cannot be broken down by the action of saprotrophs, e.g., glass, plastics.

Pesticides kill insects and pests thereby protecting the crops but these pesticides remain on the crops which enter the food chain and gets accumulated in the organisms and reaches the top most trophic level that causes diseases. When washed away by rain, it causes pollution of water.

Since non-biodegradable substances cannot be broken down into simpler forms hence they keep on accumulating in nature causing ecological imbalance.

Ecosystem is defined as a well defined unit or area in an environment where biotic and abiotic components interact with each other to maintain balance in nature. 

Biotic components – producers, consumers, saprotrophs. 

Abiotic components – air, water, sunlight.

False. 

The flow of organic matter in a food chain is bidirectional, through biogeochemical cycles, nutrients obtained after decomposition are cycled back to the soil.

A are the producers called plants and B are the secondary consumers which are called omnivores. 

Plants make their own food with the help of sunlight through the process of photosynthesis and hence are called the producers. They are places at first trophic level. Secondary consumers are the organisms that can feed both on plants and animals. They come in between primary consumers (herbivores-the plant feeders) and the tertiary consumers (carnivores-the flesh eaters.)

It is not common in a natural ecosystem, because during energy transfer from one trophic level to another most of the energy is lost in the form of heat. Hence in a natural ecosystem, we cannot see any energy transfer without a loss. 

(This will be observed 1000->100->10, instead of 1000->1000->1000)

The various steps in a food chain are called trophic levels.

(i) Environmental protection, reducing environmental pollution, concern for life.
(ii) Plastics are non-biodegradable. If they are eaten by animals they block their digestive system and if they get buried in soil it would become infertile.
(iii) (a) Totally avoid using plastics though personal action.
(b) Organise mass campaigns with the help of friends and family members.

We can adopt these methods to lessen the use of plastic: 

● Shop Friendly 

Plastic bags were once a modern convenience but can be efficiently replaced by reusable bags, many of which fold up compactly in order to be portable. Just think about how many bags you typically carry out of a grocery store, and multiply that by the number of times you grocery shop. That’s a lot of plastic! Carry a bag and always reuse plastic bags as much as possible if you have them. 

● Get Rid of Bottled 

Water People are meant to drink lots of water each day, and plastic water bottles have become a great way to stay hydrated throughout the day. However, most of these are only recommended for single use, and that means that every time someone finishes a bottle it goes into the trash. Many companies now sell reusable water bottles as a substitute, reducing plastic waste and exposure to leaking bottles. 

● Recycle Everything 

Try and select items that come in non-plastic recycled and recyclable packaging, to do your best to properly handle items that can’t be reused. Check everything before you put it in the trash, as more and more items are able to be recycled these days. 

Remember that because plastic doesn’t break down easily (if ever), recycling plastic means that it is still plastic, just being used for a different purpose. Therefore, you’re not actually reducing plastic amounts or exposure, even in the recycling process.

A food chain is a series of organisms which eat one another. And in this food chain at each level specific type of organisms occupy the same level. Hence, the trophic level is the position of a group of organisms in a food chain. It refers to the mode of nutrition at every different trophic level.

For example Plants (producers) get their nutrition from sunlight and prepare their own food. Then comes the consumers (herbivores) they cannot prepare their own food hence get their nutrition by feeding on plants. Then comes the secondary or tertiary consumers (carnivores) they get energy by eating other animals. They all get the nutrition from the organisms of lower trophic levels.

● It Upsets the Food Chain 

Because it comes in sizes large and small, polluting plastics even affect the world’s tiniest organisms such as plankton. When these organisms become poisoned due to plastic ingestion, this causes problems for the larger animals that depend on them for food. This can cause a lot of problems, each step further along the food chain. Plus, it means that plastic are present in the fish that many people eat every day. 

● Land Pollution 

When plastic is dumped in landfills, it interacts with water and form hazardous chemicals. When these chemicals seep underground, they degrade the water quality. Wind carries and deposits plastic from one place to another, increasing the land litter. It can also get stuck on poles, traffic lights, trees, fences, tower etc. and animals that may come in the vicinity and might suffocate them to death. 

● Air Pollution 

Burning of plastic in the open air, leads to environmental pollution due to the release of poisonous chemicals. The polluted air when inhaled by humans and animals affect their health and can cause respiratory problems. 

● It is Poisonous 

Man artificially makes plastic by using a number of toxic chemicals. Therefore, use of and exposure to plastics has been linked to a number of health concerns affecting people around the world. The processes of making, storing, disposing of, and just being around plastics can be extremely harmful to living things.

 ● It is Expensive 

It costs millions of dollars each year to clean affected areas after exposure, not to mention the loss of life to plants, animals, and people. As land becomes more valuable, just finding a place to put garbage is becoming a problem in many parts of the world.

Yes, plants are the producers of energy. This is the energy absorbed by the plant from sunlight for photosynthesis. Afterwards this energy is transferred to other organisms by the food chain. 

For example: Plant → Goat → Lion. 

Energy cannot be transferred back to producers because plants cannot eat animals like goat, insects, etc and without eating the energy cannot be transferred.

Green plants are called producers because they prepare food by photosynthesis using solar energy.

Green plants are also called producers because only they can synthesize organic food from inorganic raw materials with the help of solar energy in the process of photosynthesis. This food is not only used by green plants but also by other organisms called consumers.

(i) Plants, 

(ii) Tiger

Planktons are very minute or microscopic organisms freely floating on the surface of water in  a pond, lake, river or ocean.

Decomposers.

The position of the man is at the apex of most of the food chain because in a food chain the top position is mostly taken by carnivorous animals and in a normal food chain herbivores are the producers, some small organisms are the second consumers and some much larger animals are the third consumers but we come at the last. Humans can consume all most all the animals, also they are the most intelligent organisms so they can change their position by manipulation.

The bottom most trophic level has the maximum number of organisms because there have to be more food producers than consumers, to sustain life on earth. Suppose if 10 producers (plants) are there and 15 animals than 5 animals will be left hungry and will die and the eaten plants will also be not able to produce food so the remaining 10 animals will die.

B) Producers prepare their own food from ready made organic compounds.

(B) producers

Plants (30000 J) → Rat(3000 J) → Snake (300 J) → Vulture (30 J) 

According to 10% Law 

The 10% of the energy present in snakes is passed to the vultures.

Therefore, energy present in snakes =  30 x  \((\frac{100}{10})\) = 300 J

Similarly, energy present in rats = 300 x \((\frac{100}{10})\) = 3000 J

and the energy present in plants = 3000 x \((\frac{100}{10})\) = 30000 J

Second trophic level: Insects 

Fourth trophic level: Snakes

1. I suggest to use organic manures and organic insecticides to kill the insects. 

2. Rotation of crops is the best method to protect the crops from pests.

3. We should not kill any organism on this earth because every organism has a role to play. 

4. Think before you start action.

(a) False.

(b) True.

All the energy in living organisms originate from Sun.

(a)The physical and biological world together is called environment. 

(b) The non- biodegradable wastes pollutes the environment like plastic and polythene bags. 

(c) Human beings are the only organisms which change the natural environment to fulfill their needs. The uncontrolled activities of human beings are damaging the balanced and healthy environment. 

(d) Paper bags should be used for shopping because these are biodegradable whereas plastic bags are non- biodegradable.

No, change in lifestyle does not add waste to the environment. It helps to reduce the amount of waste. The use of eco-friendly products and recyclable materials will lessen the waste produced. Less use of chemical producing products, as people are becoming more aware of the consequences of disturbing the balance of nature.

 This statement is  false .

The best way to reduce the volume of solid waste is by burning waste at very high temperatures. It is the simplest and earliest form of waste disposal. But this method leads to the release of highly toxic chemicals in the environment which is harmful for the organisms.

Ozone layer absorbs the harmful Ultraviolet (UV) radiations from sunlight. Then these UV rays split molecular oxygen (O₂) into free oxygen (O), thus keeping the UV radiation from reaching the surface of the Earth.

Incineration.

Biological Magnification.

Ultra Violet radiations.

Paper and Plastics.

(i) Trees, Shrubs, 

(ii) Lion, Cheetah, 

(iii) Used and torn paper, broken pieces of wooden furniture.

(iv) Forest, Garden, 

(v) Temperature, rainfall