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Lakhmir Singh solutions Biology for Class 10 (2019 Exam) chapter 5 Our Environment

Chapters

Lakhmir Singh Biology Class 10 (2019 Exam)

Biology for Class 10 (2019 Exam)

Chapter 5 - Our Environment

Page 241

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

Q 26 | Page 241

Pages 226 - 258

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

Q 1 | Page 226

Name two natural ecosystems and two artificial ecosystems.

Q 2 | Page 226

Which one of the following is not a terrestial ecosystem?
forest, Grassland, Aquarium, Desert

Q 3 | Page 226

Why are plants called producers?

Q 4 | Page 226

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

Q 5 | Page 226

What are planktons?

Q 6 | Page 226

The following statement is true or false :
 In biology, human beings are called producers.

Q 7.1 | Page 226

The following statement is true or false :

Secondary consumers and tertiary consumers, both are carnivores.

Q 7.2 | Page 226

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

Q 8 | Page 226

Which of the following belong to the same trophic level?
Goat ; Spider ; Plants ; Hawk ; Rat

 
Q 9 | Page 226

Which of the following belong to the same trophic level?
Tree ; Frog ; Snake ; Grass ; Lizard

 
Q 10 | Page 226

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 in a food chain.

Q 11 | Page 240

Write an aquatic food chain.

 
Q 11 | Page 226

Name the organisms belonging to the second and the fourth trophic levels in the food chain comprising the following :
Frogs, Plants, Snakes, Hawk, Insects

Q 12 | Page 226

What are the various steps of food chain called?

Q 13 | Page 226

Construct a food chain comprising the following :
Snakes, Hawk, Rats, Plants

Q 14 | Page 226

Write the full name of CFC.

Q 15.2 | Page 258

Which organisms belong to third and fourth trophic levels in the food chain comprising the following?
Rats, Plants, Hawk, Snakes

Q 16 | Page 226

Which one term in the following includes the others?
air, flora, fauna, environment, water, sunlight, soil

Q 17 | Page 226

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

Q 18 | Page 226

Fill in the following blank with suitable word :
Decomposer organisms are..........in their action.

Q 19.1 | Page 226

Fill in the following blank with suitable word :

In nature, all green plants are............ whereas animals are consumers.

Q 19.2 | Page 226

Fill in the following blank with suitable word :

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

Q 19.3 | Page 226

Fill in the following blank with suitable word :

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

Q 19.4 | Page 226

Fill in the following blank with suitable word :

Plastic is a ...............material whereas paper is a.............material.

Q 19.5 | Page 226

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

Q 20 | Page 226

Name one decomposer.

Q 21.1 | Page 226

Define decomposers. 

Q 21.1 | Page 226

What is the role of decomposers in the ecosystem?

Q 21.2 | Page 226

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

Q 22 | Page 226

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

Q 23 | Page 227

Define trophic level.

Q 24.1 | Page 227

Draw the food chain with four trophic levels.

Q 24.1 | Page 227

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

Q 24.2 | Page 227

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.

Q 25 | Page 227

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?

Q 26 | Page 227

Consider the food chain :
Grass → Deer → Lion
What will happen if all the lions are removed from the above food chain?

Q 27 | Page 227

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

Q 28 | Page 227

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

Q 29 | Page 227

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

Q 30 | Page 227

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

Q 31.1 | Page 227

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

Q 31.2 | Page 227

Write down a food chain in the sea.

Q 32.1 | Page 227

Write down a food chain which ends with humans.

Q 32.2 | Page 227

Write down a food chain with five links in it.

Q 32.3 | Page 227

At which trophic level a person is feeding when he is eating roasted chicken.

Q 33.1 | Page 227

At which trophic level a person is feeding when he is eating bread.

Q 33.2 | Page 227

At which trophic level a person is feeding when he is eating eggs.

Q 33.3 | Page 227

At which trophic level a person is feeding when he is eating apple.

Q 33.4 | Page 227

At which trophic level a person is feeding when he is eating fish.

Q 33.5 | Page 227

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?

Q 34 | Page 227

Construct a long food chain.

Q 35.1 | Page 227

Construct a short foodchain, ending with man.

Q 35.2 | Page 227

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

Q 36.1 | Page 227

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

Q 36.2 | Page 227

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

Q 37 | Page 227

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

Q 38 | Page 227

Give two differences between food chain and food web.

Q 39 | Page 227

Write one or two word for the following statement/definition :
Each level of food chain where transfer of energy takes place

Q 40.1 | Page 227

Write one or two word for the following statement/definition :

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

Q 40.2 | Page 227

Write one or two word for the following statement/definition :

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

Q 40.3 | Page 227

Write one or two word for the following statement/definition :

The physical and biological world where we live in

Q 40.4 | Page 227

Write one or two word for the following statement/definition :

Selfcontained unit of living things and their non-living environment needing only sunlight for its functioning

Q 40.5 | Page 227

What is meant by biodegradable waste materials? 

Q 41.1 | Page 227

 Give two examples of biodegradable wastes.

Q 41.1 | Page 227

Which of the following materials are biodegradable?
Animal bones, Iron nails, Plastic mugs, Leather belts, Silver foil

Q 41.2 | Page 227

Give two examples of non-biodegradable wastes.

Q 42.1 | Page 227

What is meant by non-biodegradable waste materials?

Q 42.1 | Page 227

Which of the following materials are biodegradable?
Animal bones, Iron nails, Plastic mugs, Leather belts, Silver foil

Q 42.2 | Page 227

Give examples of any two ecosystems.

Q 43.1 | Page 228

Define an ecosystem.

Q 43.1 | Page 228

List the biotic and abiotic components of an ecosystem.

Q 43.2 | Page 228

What is a food chain?

Q 44.1 | Page 228

Give one example of a simple food chain.

Q 44.1 | Page 228

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

Q 44.2 | Page 228

What is meant by 'environment'?

Q 45.1 | Page 228

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

Q 45.2 | Page 228

 Name the organisms whose uncontrolled activities are damaging the environment.

Q 45.3 | Page 228

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

Q 45.4 | Page 228

Which of the following constitute a food-chain?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat

Q 46 | Page 228

In a food chain, the initial organism is usually :
(a) photosynthetic
(b) herbivore
(c) saprophytic
(d) parasitic

Q 47 | Page 228

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

Primary
producers
Primary consumers Secondary
consumers
(a) green algae fish mosquito larvae
(b) fish green algae mosquito larvae
(c) mosquito larvae fish green algae
(d) green algae mosquito larvae fish

 

Q 48 | Page 228

Which of the following are decomposers of dead organisms?

Bacteria Fungi Viruses
(a) no yes yes
(b) yes no yes
(c) yes yes  no
(d) yes yes yes
Q 49 | Page 228

Which of the following is an artificial ecosystem?
(a) pond
(b) crop field
(c) lake
(d) forest

Q 50 | Page 228

Disposable plastic plates should not be used because :
(a) they are made of light weight materials
(b) they are made of toxic materials
(c) they are made of biodegradable materials
(d) they are made of non-biodegradable materials

Q 51 | Page 228

In a food chain, the third trophic level is always occupied by :
(a) carnivores
(b) herbivores
(c) decomposers
(d) producers

Q 52 | Page 228

Accumulation of non-biodegradable pesticides in the food chain in increasing amount at each higher trophic level is known as :
(a) eutrophication
(b) pollution
(c) biomagnification
(d) accumulation

Q 53 | Page 228

If a grasshopper is eaten by a frog, then the energy transfer will be from :
(a) producer to decomposer
(b) producer to primary consumer
(c) primary consumer to secondary consumer
(d) secondary consumer to tertiary consumer

Q 54 | Page 228

An ecosystem includes :
(a) all living organisms
(b) non-living objects
(c) both living organisms and non-living objects
(d) all living organisms and input of sun's energy

Q 55 | Page 228

The decomposers in an ecosystem :
(a) convert inorganic material to simpler forms
(b) convert organic material to inorganic forms
(c) convert inorganic material into organic compounds
(d) do not break down organic compounds

Q 56 | Page 228

What will happen if deer is missing in the food chain given below?
Grass → Deer → Tiger
(a) The population of tigers increases
(b) the population of grass decreases
(c) Tigers will start eating grass
(d) The population of tigers decreases and the population of grass increases.

Q 57 | Page 229

Organisms which synthesise carbohydrates from inorganic compounds by using radiant energy are called :
(a) decomposers
(b) producers
(c) herbivores
(d) carnivores

Q 58 | Page 229

Organisms of a higher trophic level which feed on several types of organisms belonging to a number of lower trophic levels constitute the :
(a) ecosystem
(b) food web
(c) ecological pyramid
(d) food chain

Q 59 | Page 229

n 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

(a) (iii)
(b) (iv)
(c) (i) and (iii)
(d) (ii) and (iv)

Q 60 | Page 229

Which of the following statement is incorrect?
(a) all green plants and blue green algae are producers
(b) green plants get their food from readymade organic compounds
(c) producers prepare their own food from inorganic compounds
(d) plants convert solar energy into chemical energy

Q 61 | Page 229

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

(a) (i) and (iii)
(b) (iii) and (iv)
(c) (ii) and (iii)
(d) (i) and (iv)

Q 62 | Page 229

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?
(a) T4
(b) T2
(c) T1
(d) T3
Figure

Q 63 | Page 229

One of the following is not a biodegradable material. This one is :
(a) cotton
(b) animal bones
(c) aluminium foil
(d) wood

Q 64 | Page 229

Which of the following is not a non-biodegradable material?
(a) nylon socks
(b) plastic school bag
(c) jute carry bag
(d) polyester clothes

Q 65 | Page 229

The use of one of the following will pollute the environment. This one is :
(a) paper carry bags
(b) cotton cloth carry bags
(c) nylon cloth carry bags
(d) jute carry bags

Q 66 | Page 229

One of the following is not a consumer. This one is :
(a) giraffe
(b) antelope
(c) algae
(d) alligator

Q 67 | Page 229

Which of the following is not a producer?
(a) grass
(b) zooplankton
(c) phytoplankton
(d) paddy

Q 68 | Page 229

One of the following is a micro-consumer. This one is :
(a) ant
(b) lice
(c) fungi
(d) mosquito

Q 69 | Page 229

Which of the following act as decomposers in an ecosystem?
(a) Lactobacillus bacteria
(b) Cyanobacteria
(c) Putrefying bacteria
(d) Rhizobium bacteria

Q 70 | Page 229

One of the following helps in the recycling of materials in an ecosystem. This one is :
(a) autotrophs
(b) saprotrophs
(c) omnivores
(d) carnivores

Q 71 | Page 229

In the food chain comprising of a snake, grass, insect, and frog, the secondary consumer is :
(a) insect
(b) snake
(c) frog
(d) grass

Q 72 | Page 229

Sahara Desert was formed over a period of time due to one of the following uncontrolled activities of man :
(a) excessive cutting down of forest plants and trees
(b) excessive killing of large herbivores
(c) excessive killing of large carnivores
(d) excessive use of poisonous chemicals herbicides

Q 73 | Page 229

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

Write a food chain comprising all the given organisms.

 

Q 74.1 | Page 230

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

Which organisms in the food chain are herbivore, and carnivores?

Q 74.2 | Page 230

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

Which organisms are (i) predators, and (ii) prey?

Q 74.3 | Page 230

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

Which organisms can trap solar energy to make food?

Q 74.4 | Page 230

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

Which organism is a secondary consumer?

Q 74.5 | Page 230

The following is a food chain that ends with human :
plants → bee → human

Explain how plants provide food for bees.

Q 75.1 | Page 230

The following is a food chain that ends with human :
plants → bee → human

How do bees provide food for humans?

Q 75.2 | Page 230

The following is a food chain that ends with human :

How does this food chain differ form a usual food chain involving human such as : plants → goat → human?

Q 75.3 | Page 230

The following is a food chain that ends with human :

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

Q 75.4 | Page 230

A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y

Name one phytoplankton.

Q 76.1 | Page 230

A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y

Name two zooplanktons.

Q 76.2 | Page 230

A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y

What could be X?

Q 76.3 | Page 230

A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y

Name the organism which Y could be.

Q 76.4 | Page 230

A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y

Which organism in the above food chain is a (1) primary consumer, and (2) tertiary consumer?

Q 76.5 | Page 230

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 and 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 form the food chain such as : plants → goat → man?

Q 77 | Page 230

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

Q 78.1 | Page 230

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

Q 78.2 | Page 230

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

Q 79.1 | Page 230

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

Q 79.2 | Page 230

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

Column I Column II Column III
(1) Secondary consumer Herbivore 1st trophic level
(2) Primary consume Autotroph 3rd trophic level
(3) Producer Carnivore 4th trophic level
(4) Tertiary consumer Large carnivore 2nd trophic level
Q 80.1 | Page 231

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.

Q 80.2 | Page 231

Pages 240 - 244

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

Q 1 | Page 240

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

Q 2 | Page 240

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

Q 3 | Page 240

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

Q 4 | Page 240

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?

Q 5 | Page 240

Which radiations are absorbed by ozone layer?

Q 6 | Page 240

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

Q 7 | Page 240

Name two waste materials which can be recycled.

Q 8 | Page 240

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

Q 9 | Page 240

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

Q 10 | Page 240

Where does all the energy in living organisms originate from?

Q 12 | Page 240

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

Q 13 | Page 240

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

Q 14 | Page 240

Fill in the following blank with suitable word :

Ultraviolet rays can cause skin..............

Q 15.1 | Page 240

Fill in the following blank with suitable word :

Pesticides enter the food chain at the ...........level

Q 15.2 | Page 240

Fill in the following blank with suitable word :

 Grass → ........... → Human

Q 15.3 | Page 240

Fill in the following blank with suitable word :

Lettuce → ............. → Fox

Q 15.4 | Page 240

Fill in the following blank with suitable word :

Plants → Antelope → ............

Q 15.5 | Page 240

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

Q 16 | Page 241

Write the full name of CFC.

Q 17.1 | Page 241

Give one harmful effect of CFC.

Q 17.2 | Page 241

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

Q 18 | Page 241

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

Q 19 | Page 241

Explain how harmful chemicals enter our bodies.

Q 20 | Page 241

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

Q 21 | Page 241

What is biological magnification?

Q 22.1 | Page 241

 With the help of a food chain, explain how biological magnification of harmful chemicals can occur.

Q 22.2 | Page 241

What is meant by bioconcentration of pesticides

Q 23.1 | Page 241

Which common pesticide has accumulated in human body in considerable amounts?

Q 23.2 | Page 241

What is garbage?

Q 24.1 | Page 241

What does garbage consist of?

Q 24.2 | Page 241

Name the various modes of waste disposal.

Q 25 | Page 241

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

Q 27 | Page 241

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

Q 28 | Page 241

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

Q 29 | Page 241

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

Q 30 | Page 241

What is sewage? How is sewage disposed of?

Q 31 | Page 241

Write the harmful effects of ozone depletion.

Q 32 | Page 241

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

Q 33 | Page 241

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

Q 34.1 | Page 241

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

Q 34.2 | Page 241

What is ozone? 

Q 35.1 | Page 241

How Ozone is Formed?

Q 35.1 | Page 241

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

Q 35.2 | Page 241

What is UNEP?

Q 35.3 | Page 241

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

Q 35.3 | Page 241

How is energy introduced into the ecosystem?

Q 36.1 | Page 241

Consider the following food chain

(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.:

Q 36.2 | Page 241

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

Q 37.1 | Page 241

 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

Q 37.2 | Page 241

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

Q 38.1 | Page 241

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?

Q 38.2 | Page 241

What provides the energy which then flows through a food chain?
(a) glucose
(b) oxygen
(c) respiration
(d) sunlight

Q 39 | Page 242

Which pollutant released into the air during refrigeration and airconditioning is the greatest contributor to the depletion of ozone layer?
(a) BHC
(b) DDT
(c) CFC
(d) UNEP

Q 40 | Page 242

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?
Grass → Grasshopper → Frog → Snake → Hawk
(a) 500 kJ
(b) 50 kJ
(c) 5000 kJ
(d) 5 kJ

Q 41 | Page 242

Which of the following limits the number of trophic levels in a food chain?
(a) insufficient food supply from producer level
(b) decrease in energy at higher trophic levels
(c) increase in the number of organisms at higher trophic levels
(d) accumulation of harmful chemicals at higher trophic levels

Q 42 | Page 242

What percentage of sun's energy falling on the leaves of green plants is utilised by the plants in the process of photosynthesis and stored as chemical energy of food?
(a) 99 per cent
(b) 10 per cent
(c) 1 per cent
(d) 20 per cent

Q 43 | Page 242

The depletion of ozone layer in the upper atmosphere is mainly due to the emission of :
(a) unburnt hydrocarbons
(b) chlorofluorocarbons
(c) greenhouse gases
(d) ultraviolet radiations

Q 44 | Page 242

In an ecosystem, the ten per cent energy available for transfer from one trophic level to the next is in the form of :
(a) heat energy
(b) light energy
(c) chemical energy
(d) mechanical energy

Q 45 | Page 242

The flow of energy in an ecosystem is always :
(a) unidirectional
(b) bidirectional
(c) cyclic
(d) multidirectional

Q 46 | Page 242

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

(a) (i) and (ii)
(b) (ii) and (iv)
(c) (i) and (iii)
(d) (iii) and (iv)

Q 47 | Page 242

Which of the following gets the minimum energy through the food chain in an ecosystem?
(a) carnivore
(b) large carnivore
(c) producer
(d) herbivore

Q 48 | Page 242

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 :
(a) cat
(b) plants
(c) dog
(d) seed-eating bird

Q 49 | Page 242

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 :
(a) water beetles
(b) tadpoles
(c) weeds
(d) fish

Q 50 | Page 242

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?
(a) big fish
(b) bird
(c) larvae
(d) small fish

Q 51 | Page 242

If the energy available at the producer level in a food chain is 150 J, how much energy will be transferred to : tertiary consumer?
(a) 15 J
(b) 10 J
(c) 1.50 J
(d) 0.15 J

Q 52 | Page 242

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?
(a) snake
(b) eagle
(c) mice
(d) peacock

Q 54 | Page 242

Which of the following is the best method to dispose of biological wastes from hospitals?
(a) landfill
(b) recycling
(c) incineration
(d) composting

Q 55 | Page 243

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.

(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (i) and (iii)

Q 56 | Page 243

The ten per cent law is associated with
(a) transfer of energy from various trophic levels to decomposers in a food chain
(b) transfer of ATP energy into muscular energy
(c) transfer of chemical energy from one organism to another
(d) transfer of sun's energy to the organisms called producers.

Q 57 | Page 243

The harmful chemical which is accumulating in human beings through food chain is :
(a) benzenehexachloride
(b) dichlorodiphenyltrichloroethane
(c) chlorofluorocarbon
(d) abscisic acid

Q 58 | Page 243

O2 is converted into O3 by the action of :
(a) infrared radiations
(b) ultraviolet radiations
(c) gamma radiations
(d) cosmic radiations

Q 59 | Page 243

Which of the following cannot be added in a composting pit to prepare compost?
(a) sunflower plants
(b) fruit and vegetable peels
(c) flowers of plastic
(d) red worms

Q 60 | Page 243

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 prevent 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 C over 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.

Q 61 | Page 243

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?

Q 62 | Page 243

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.

Q 63 | Page 243

A food chain consists of fish, larvae, phytoplanktons and birds. The level of pesticides in water in which the fish, larvae and phytoplanktons live is quite high.
(a) In which organisms the pesticides enter from the polluted water? What is this level of organisms known as?

Q 64.1 | Page 244

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

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

Q 64.2 | Page 244

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

Write the food chain comprising all the organisms mentioned above.

Q 64.3 | Page 244

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

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

Q 64.4 | Page 244

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 institutions. Name such institutions.

Q 65 | Page 244

Lakhmir Singh Biology Class 10 (2019 Exam)

Biology for Class 10 (2019 Exam)
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