What is the functional unit of the environment comprising of the living and non-living components called?

Name two natural ecosystems and two artificial Ecosystems.

Which one of the following is not a terrestrial ecosystem?

Forest, Grassland, Aquarium, Desert

Why are plants called producers?

What name has been given to those organisms which break down the complex organic compounds present in dead animals and plants?

What are planktons?

State whether the following statements are true or false:

(a) In biology, human beings are called producers.

(b) Secondary consumers and tertiary consumers, both are carnivores.

Which category of organisms forms the starting point of a food chain?

Which of the following belong to the same trophic level?

Goat; Spider; Plants; Hawk; Rat

Which of the following belong to the same trophic level?

Tree; Frog ; Snake ; Grass ; Lizard

Write an aquatic food chain.

Name the organisms belonging to the second and the fourth trophic levels in the food chain comprising the following:

Frogs, Plants, Snakes, Hawk, Insects

What are the various steps of food chain called?

Construct a food chain comprising the following: Snakes, Hawk, Rats and plant.

Arrange the following in a food chain: Fish, Algae, Small animals, Big Fish

Which organisms belong to third and fourth trophic levels in the food chain comprising the following?

Rats, Plants, Hawk, Snakes

Which one term in the following includes the others?

Air, flora, fauna, environment, water, sunlight, soil

A food chain represents a unidirectional flow of X. What is X?

Fill in the following blanks with suitable words:

(a) Decomposer organisms are................in their action.

(b) In nature, all green plants are..................... whereas animals are consumers.

(c) A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a..................

(d) The science that deals with the inter-relationships of living things with one another and their environment is called....................

(e) Plastic is a ......................material whereas paper is a..................material.

Explain the terms 'producer' and 'consumer'. Give two examples of producers and two of consumers.

Define decomposers. Name one decomposer.

What is the role of decomposers in the ecosystem?

What is meant by a primary consumer, secondary consumer and a tertiary consumer? Give one example of each.

Give an example of a four step food chain operating in grassland. Name the secondary consumer in this food chain.

Define trophic level. Draw the food chain with four trophic levels.

What will happen if we kill all the organisms in one trophic level?

What is the difference between the food habits of organisms belonging to the first and the third trophic levels? Give one example each of the organisms belonging to these two trophic levels.

Can the organisms of any trophic level be removed without causing any damage to the ecosystem? Will the impact of removing all the organisms in a trophic level be different for different trophic levels?

Consider the food chain:

● Grass Deer Lion

What will happen if all the lions are removed from the above food chain?

The number of malaria patients in a village increased tremendously when large numbers of frog were exported from the village. What could be the cause for it?

How does a biodegradable waste differ from a non-biodegradable waste? Give two examples of non �-biodegradable wastes which pollute our environment.

Which of the following are biodegradable and which non-biodegradable?

● Glass bottle, Paper, Ball point pen refill, Hay, DDT, Wheat, Cake, Wood, Polythene bag, Jute bag, Cotton cloth, Grass, Vegetable peels

Describe an activity to show that while paper is biodegradable but plastic (say, polythene) is non- biodegradable.

Explain why, some materials are biodegradable but some are non-biodegradable.

Write down a food chain:

(a) In the sea

(b) Which ends with human-beings

(c) With five links in it.

At which trophic level a person is feeding when he is eating:

(a) Roasted chicken

(b) Bread

(c) Eggs

(d) Apple

(e) Fish

A student went to study a local pond. In one part of the pond she noticed tadpoles scraping at some pond weed. In another part she saw a water beetle holding a tadpole in its jaws.

(a) Construct a food chain for the pond.

(b) How many links are there in this chain?

Construct.

(a) a long food chain, and

(b) a short food chain, ending with man.

State one advantage of using jute bags over plastic bags for shopping.

Write a common food chain of a pond ecosystem having four links.

We do not clean ponds or lakes but an aquarium needs to be cleaned periodically. Why?

What will be the consequence of the absence of decomposers in the ecosystem?

Give two differences between food chain and food web.

Write one or two words for each of the following statements/definitions:

(a) Each level of food chain where transfer of energy takes place

(b) The physical factors like temperature, rainfall, light, soil, air and water of an ecosystem

(c) Organisms which depend on the producers for food either directly or indirectly

(d) The physical and biological world where we live in

(e) Self-contained unit of living things and their non-living environment needing only sunlight for its functioning

What is meant by biodegradable waste materials? Give two examples of biodegradable wastes.

Which of the following materials are non-biodegradable?

Aluminum wire, Tea leaves, Synthetic fibre, wool

What is meant by non-biodegradable waste materials ? Give two examples of non-biodegradable wastes.

Which of the following materials are biodegradable?

Animal bones, Iron nails, Plastic mugs, Leather belts, Silver foil

Define an ecosystem. Give examples of any two ecosystems.

List the biotic and abiotic components of an ecosystem.

What is a food chain? Give one example of a simple food chain.

What is a 'food web'? Show its formation.

What is meant by 'environment'?

What type of substances are the major pollutants of the environment? Name two such substances.

Name the organisms whose uncontrolled activities are damaging the environment.

Explain why, it is better to use paper bags than plastic bags.

Which of the following constitutes a food chain?

In a food chain, the initial organism is usually:

Which of the following represents a possible food chain found in a pond:

Which of the following are decomposers of dead organisms?

Which of the following is an artificial ecosystem?

Disposable plastic plates should not be used because:

In a food chain, the third trophic level is always occupied by:

Accumulation of non-biodegradable pesticides in the food chain in increasing amount at each higher trophic level is known as:

If a grasshopper is eaten by a frog, then the energy transfer will be from:

An ecosystem includes:

The decomposers in an ecosystem:

What will happen if deer is missing in the food chain given below?

Grass → Deer → Tiger

Organisms which synthesize carbohydrates from inorganic compounds by using radiant energy are called:

Organism of a higher trophic level which feed on several types of organisms belonging to a number of lower trophic levels constitute the:

In the following groups of materials, which group/groups contain only non-biodegradable materials ?

(i) wood, paper, leather

(ii) polythene, detergent, PVC

(iii) plastic, detergent, grass

(iv) plastic, Bakelite, DDT

Which of the following statement is incorrect?

Which of the following group of organisms are not constituents of a food chain?

(i) Grass, lion, rabbit, wolf

(ii) Plankton, man, fish, grasshopper

(iii) Wolf, grass, snake, tiger

(iv) Frog, snake, eagle, grass, grasshopper

In the figure given alongside, the various trophic levels are shown in the form of a pyramid. At which trophic level the maximum energy is available?

One of the following is not a biodegradable material. This one is:

Which of the following is not a non-biodegradable material?

The use of one of the following will pollute the environment. This one is:

One of the following is not a consumer. This one is:

Which of the following is not a producer?

One of the following is a micro-consumer. This one is:

Which of the following act as decomposers in an ecosystem?

One of the following helps in the recycling of materials in an ecosystem. This one is:

In the food chain comprising of a snake, grass, insect, and frog, the secondary consumer is:

Sahara Desert was formed over a period of time due to one of the following uncontrolled activities of man:

The sea water contains water beetles, tadpole, fish and weeds.

(a) Write a food chain comprising all the given organisms.

(b) Which organisms in the food chain is

(i) Herbivore

(ii) Carnivore

(c) Which organisms are

(i) Predators

(ii) Prey

(d) Which organisms can trap solar energy to make food?

(e) Which organism is a secondary consumer?

The following is a food chain that ends with human:

Plants → bee → human

(a) Explain how plants provide food for bees.

(b) How do bees provide food for humans?

(c) How does this food chain differ from a usual food chain involving human such as: plants goat human?

(d) Do you think that the food chain given in this question can really be regarded as a food chain? Explain your answer.

A food chain occurring in the sea which provides food for many people can be written as:

Phytoplankton → Zooplankton → X → Y

(a) Name one phytoplankton.

(b) Name two zooplanktons.

(c) What could be X?

(d) Name the organism which Y could be.

(e) Which organism in the above food chain is a

(i) Primary consumer, and

(ii) Tertiary consumer

Some hunters are roaming in the plush green forest of Africa. They spot a deer and kill it. They decide to roast the deer there and then eat it. When the hunters had just finished enjoying the feast of roasted deer, a lion attacks them. The lion kills one of the hunters and eats his flesh.

(a) Write a food chain which provides food to lion in this case.

(b) Which animal (other than deer) the lion could look for food if he did not get the hunter as prey?

(c) Which other animal in the forest could have been in place of lion?

(d) How does the above food chain differ from the food chain such as:

plants → goat → man?

a) Humans are at the end of most of the food chains in which they occur (as this picture of man taking home a fish for food shows)

b) But sometimes luck runs out and humans are forced to become food for others (as this picture of lion eating a man shows). Here the human is no longer at the end of food chain. Look at the miracle of GOD: hunter has become hunted!

What would happen to the number of rabbits and grass plants if the number of foxes:

(a) Increased

(b) Decreased

What would happen to the number of grass plants and foxes if the number of rabbits:

(a) Increased

(b) Decreased

Match the terms given in column I with the terms given in column II and column III having the same meaning:

Give one example of a food chain having four organisms. Below each organism write the three appropriate terms from the part (a) above which you think it represents.

What percentage of the solar energy is trapped and utilized by the plants?

What percentage of energy available at the producer level is transferred at successive trophic levels in a food chain?

Name the process in which a harmful chemical enters the food chain and gets concentrated at each trophic level.

In a food chain consisting of grass, frog, bird and insects, where will the concentration of the harmful chemical be maximum?

If a harmful chemical enters a food chain comprising cat, mice and plants, which one of these organisms is likely to have the maximum concentration of the harmful chemical in its body?

Which radiations are absorbed by ozone layer?

Name the group of chemical compounds which damages the ozone layer.

Name two waste materials which can be recycled.

Name the process by which the volume of solid wastes can be reduced.

If 5 joules of energy is available at producer level (plants), then how much energy will be transferred to the lion in the following food chain?

Plants Goat Lion

State whether the following statement is true or false:

Only 10 per cent of the light energy given by the sun is available for transfer at each higher trophic level a food chain.

Where does all the energy in living organisms originate from?

Why are there rarely more than five links (or five organisms) in a food chain?

Name two predators of snakes in a food web operating in a forest ecosystem.

Fill in the following blanks with suitable words :

(a) Ultraviolet rays can cause skin.................

(b) Pesticides enter the food chain at the ..............level

(c) Grass ………………………. Human

(d) lettuce …………………………. Fox

(e) Plants Antelope ……………….

What is ten per cent law? Explain with an example.

Write the full form of CFC. Give its one harmful effect.

Explain how, harmful ultraviolet radiations of sunlight are prevented from reaching the earth's surface.

What are the causes of depletion of ozone layer? Which diseases are likely to be caused if the ozone layer will become thinner?

Explain how harmful chemicals enter our bodies.

'If we excessively use pesticides to protect the crops from diseases, then it may cause long -term damage to mankind'. Justify this statement.

What is meant by biological magnification? With the help of a food chain, explain how biological magnification of harmful chemicals can occur.

What is meant by bio-concentration of pesticides? Which common pesticide has accumulated in human body in considerable amounts?

What is garbage? What does garbage consist of?

Name the various modes of waste disposal.

How can the wastes such as paper, plastic and metal objects be disposed of?

Give a method for the disposal of household wastes such as left-over food, fruit and vegetable peels, and leaves of potted plants.

What is meant by incineration? For what purpose is it used?

How are most of the solid wastes in urban areas disposed of?

State two advantages of using disposable paper cups over disposable plastic cups.

What is sewage? How is sewage disposed of?

Write the harmful effects of ozone depletion.

What would happen if the ozone layer in the atmosphere completely disappears?

With the help of a flow diagram, describe how energy from the sun flows through various trophic levels.

Explain why, the flow of energy in the ecosystem is said to be unidirectional.

What is ozone? How is it formed?

How does ozone layer protect us from harmful effects in the environment?

What is UNEP? What step has been taken by UNEP in 1987 to prevent too much damage to the ozone layer?

How is energy introduced into the ecosystem?

Consider the following food chains:

(i) Plants Mice Snakes Hawks

(ii) Plants Mice Hawks

If energy available at the producer level in both the food chains is 100 J, in which case will hawks get more energy as food and by how much? Justify your answer.

Explain why, a food chain usually cannot have more than three or four steps.

Calculate the amount of energy that will be available to big fish in the following food chain, if 10,000 J of energy is available to small algae from the sun:

Small algae Zooplankton Fish Big fish

Name and state the law given by Lindeman which tells us how much energy entering a particular trophic level of organisms is available for transfer to the next higher trophic level.

How much energy will be available to hawks in the food chain comprising hawk, snake, paddy and mice, if 10,000 J of energy is available to paddy from the sun?

What provides the energy which then flows through a food chain?

Which pollutant released into the air during refrigeration and air-conditioning is the greatest contributor to the depletion of ozone layer?

In the food chain given below, if the amount of energy available at fourth trophic level is 5 kJ, what was the energy available at the producer level?

GrassGrasshopper Frog Snake Hawk

Which of the following limits the number of trophic levels in a food chain?

What percentage of sun's energy falling on the leaves of green plants is utilized by the plants in the process of photosynthesis and stored as chemical energy of food?

The depletion of ozone layer in the upper atmosphere is mainly due to the emission of:

In an ecosystem, the ten per cent energy available for transfer from one trophic level to the next is in the form of:

The flow of energy in an ecosystem is always:

The excessive exposure of humans to ultraviolet rays results in:

(i) Damage to immune system

(ii) Damage to lungs

(iii) Skin cancer

(iv) Peptic ulcers

Which of the following gets the minimum energy through the food chain in an ecosystem?

A food chain comprises of cat, seed-eating bird, plants, and dog. The organism which will have the maximum concentration of harmful pesticides coming through the food chain is most likely to be:

An aquatic food chain comprises of the organisms like tadpoles, weeds, fish and water beetles. The organism which gets the minimum energy through this food chain is:

Most of the water surface of a lake is covered with algae. This algae is part of the food chain which also includes small fish, bird, larvae and big fish. Which of the following will obtain the maximum energy?

If the energy available at the producer level in a food chain is 150 J, how much energy will be transferred to: tertiary consumer?

If the energy transferred to a tertiary consumer in a food chain is 10 J, how much energy was available to the primary consumer?

In addition to wheat plants, a crop field ecosystem has organisms such as snake, peacock, eagle and mice. If the wheat plants are sprayed with pesticides periodically, which of the following will have the minimum concentration of pesticides in the body?

Which of the following is the best method to dispose of biological wastes from hospitals?

In an ecosystem:

(i) The flow of energy is unidirectional

(ii) The flow of materials is unidirectional

(iii) The flow of materials is cyclic

(iv) The flow of energy is cyclic

The ten per cent law is associated with

The harmful chemical which is accumulating in human beings through food chain is:

O₂ is converted into O₃ by the action of:

Which of the following cannot be added in a composting pit to prepare compost?

The gas A is used by most of the animals to obtain energy from food by the process of respiration. When A is acted upon by radiation X, it gets converted into another gas B which is an allotrope of A but poisonous when inhaled. B forms a kind of layer C in the upper atmosphere which absorbs radiations X coming from a source Y and prevents them from reaching the earth. Some chemicals Z released from the various devices on the earth are destroying the layer C slowly. In fact, a hole has already been formed in layer Cover the area D of the earth.

(a) What are gases?

(i) A, and

(ii) B? Write their molecular formulae.

(b) Name the layer C.

(c) What are (i) X, (ii) Y, and (iii) Z?

(d) Name the area D.

(e) Name any two human ailments which may be caused by X.

The surface of water in a lake appears green due to a layer of tiny free-floating organisms X on its surface. The lake water also contains organisms like water beetle, fish and tadpole. The sun shines over the lake water and provides energy for the functioning of this lake ecosystem.

(a) What could organisms X be?

(b) Write a food chain comprising of all the four organisms mentioned.

(c) What is the general name of the food chains like the one written above?

(d) Name

(i) Secondary consumer

(ii) Producer

(iii) Tertiary consumer, and

(iv) Primary consumer in the above food chain

(e) If the tertiary consumer gets 0.2 J of energy from the secondary consumer, then how much energy was radiated by the sun to the producer?

A forest ecosystem having a lot of green plants has some foxes, lions and rabbits in it.

(a) Write a food chain comprising all the four organisms mentioned above.

(b) Name

(i) one herbivore, and

(ii) two carnivores, in this food chain.

(c) Name the link which is a predator as well as a prey.

(d) Name

(i) second trophic level, and

(ii) third trophic level.

(e) Which link of this food chain can feed on second trophic level as well as third trophic level, independently?

(f) If the sun provides 1000 J of energy to the plants, then how much energy will be transferred to fox through the food chain.

A food chain consists of fish, larvae, phytoplankton and birds. The level of pesticides in water in which the fish, larvae and phytoplankton live is quite high.

(a) In which organisms the pesticides enter from the polluted water? What is this level of organisms known as?

(b) Which organism will have the maximum amount of pesticides accumulated through the food chain? What is this process known as?

(c) Write the food chain comprising all the organisms mentioned above.

(d) Which other organism you could write in place of bird in the above food chain?

Every household produces a lot of material A daily. In one of the methods of disposal B, material A is burned at a very high temperature of about 1000°C in a structure called C. During this process, the organic matter present is removed as D and E whereas F is left behind (which can be dumped in a landfill site).

(a) What is material A

(b) Name the method of disposal B.

(c) What is structure C known as?

(d) What are

(i) D

(ii) E, and

(iii) F?

(e) This method is especially suitable for the disposal of materials produced by certain institution. Name such institutions.