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Conservation Of Environment Class 10th Science Tamilnadu Board Solution

Class 10th Science Tamilnadu Board Solution
Part-a
  1. Which of the following groups contain only bio-degradable items?A. Grass, flowers and…
  2. Which of the following groups contain only bio-degradable items?A. Grass, flowers and…
  3. Which of the following constitutes a food chain?A. Grass, wheat and mango B. Grass, goat…
  4. Which of the following are environmental friendly practices?A. Carrying cloth bags for…
  5. What is called as ‘black gold’?A. hydrocarbons B. coal C. petroleum D. ether…
  6. Based on the food chain, pick the odd one out: plants → grasshopper → frog → tiger → snake…
  7. Example for product of green chemistry is _____________.A. plastic B. paper C. bio…
  8. ________ is a greenhouse gas which causes climate change and global warming.A. hydrogen B.…
  9. The ________ form decomposers in the pond ecosystem.A. plants B. bacteria C. frogs D.…
  10. _________ is used in seeding clouds.A. potassium iodide B. calcium carbonate C.…
  11. An example for fossil fuel is _________ .A. copper B. iron C. magnesium D. coal…
  12. Air pollution is caused by transport exhaust fumes and emission of gases like SO2, CO2,…
  13. If wild animals are killed, what difficulty would we face?A. imbalance in nature B.…
  14. Water is an essential commodity for survival. What can we do to help increase water…
  15. The tiger and the lion are carnivores. Likewise, the elephant and the bison…
  16. Assertion (A): Coal and petroleum are called fossil fuels. Reason (R): Fossil fuels are…
  17. Compressed Natural Gas (CNG) is considered a better fuel than coal/ petroleum, because…
  18. Now-a-days water bottles and lunch boxes are made from agricultural products like fruit…
Part-b
  1. Classify the following into producers, consumers, decomposers. i) butterfly ii) grass…
  2. Living organisms adapt themselves according to their habitat. Match the following: -…
  3. Fill in the blanks i) Animals give out ________ through respiration. ii) In the presence…
  4. Bacteria and fungi are responsible for the decay of dead plants and animals. Decaying…
  5. Fill in the blanks with suitable answers from those given in the brackets. (harmful, heavy…
  6. Depict a food chain by placing the following organisms in the correct trophic levels:…
  7. Show an aquatic food chain using the following organisms. (Small fish, Phytoplanktons,…
  8. (i) Find out the wrong statement: a) ‘A’ is a producer b) ‘F’ is a herbivore c) ‘H’ is an…
  9. Find out how many food chains are present in the above food web. Observe the following…
  10. Observe the following Bio-geo chemical cycle. i) Mention the nutrient in the given cycle.…
  11. Study the food chain below, correct it and convert it into a pyramid of energy. Mulberry →…
  12. Study the illustration and answer the questions: i) Which line (A or B) represents the…
  13. i) Name the processes noted as No. 1 and 3. ii) Define process 1.…
Part-c
  1. i) Classify the following substances - wood, paper, plastic and grass. ii) Give a detailed…
  2. In your locality people are affected due to water scarcity. What measures will you take to…
  3. We are surrounded by smoke. Is this situation good for our health? Give reason.…
  4. List out the harmful effects of burning coal.
Part-a
Question 1.

Which of the following groups contain only bio-degradable items?
A. Grass, flowers and leaves

B. Grass, wood and plastic

C. Fruit peels, cake and plastic

D. Cake, wood and glass


Answer:

Group (i) contains only bio-degradable items, these are the substances which can be broken down by biological processes or microbial action.

Plastics and glass are non-biodegradable substances, which are there in other options, hence eliminated.


Question 2.

Which of the following groups contain only bio-degradable items?
A. Grass, flowers and leaves

B. Grass, wood and plastic

C. Fruit peels, cake and plastic

D. Cake, wood and glass


Answer:

Group (i) contains only bio-degradable items, these are the substances which can be broken down by biological processes or microbial action.

Plastics and glass are non-biodegradable substances, which are there in other options, hence eliminated.


Question 3.

Which of the following constitutes a food chain?
A. Grass, wheat and mango

B. Grass, goat and human

C. Goat, cow and elephant

D. Grass, fish and goat


Answer:

The second option shows correct order of a food chain as Grass is eaten by goat and non-vegetarian human beings eat meat of goat.


Question 4.

Which of the following are environmental friendly practices?
A. Carrying cloth bags for shopping

B. Switching off light and fans when not in use

C. Using public transport

D. All the above


Answer:

All the options given are environmental friendly practices. We should Carry cloth bags for shopping so as to minimize the use of plastic bags. We should Switching off light and fans when not in use to conserve the electrical energy. We should opt for public transports for most of the time, this helps in checking noise pollution.


Question 5.

What is called as ‘black gold’?
A. hydrocarbons

B. coal

C. petroleum

D. ether


Answer:

Due to its great commercial importance petroleum is also called ‘black gold’.


Question 6.

Based on the food chain, pick the odd one out:

plants → grasshopper → frog → tiger → snake


Answer:

Tiger

The above food chain tells that plants are eaten by grasshopper, grasshopper is eaten by frog, which are correct till now. Next it tells frog is eaten by tiger, which is not actually true. So, it breaks the general trend in the food chain given in the question. But it can be rectified by putting tiger after snake. So, the correct order will be:


plants → grasshopper → frog → snake → tiger


which then removes the odd point an tell us that frog is eaten by snake and snake is eaten by tiger which is true infect.



Question 7.

Example for product of green chemistry is _____________.
A. plastic

B. paper

C. bio plastics

D. halogen flame retardants


Answer:

Green chemistry is the design of chemical products and the processes to reduce or eliminate the use and generation of hazardous substances. Plastics as we know is non-biodegradable hence a hazardous substance. Bio plastics on the other hand are bio degradable hence environmental friendly. Paper production use various chemicals which can contaminate water when brought in touch. Halogen retardant flames are hazardous. We rather prefer to use halogen free flame retardants.


Question 8.

________ is a greenhouse gas which causes climate change and global warming.
A. hydrogen

B. oxygen

C. nitrogen

D. carbondioxide


Answer:

Greenhouse gases are gases which causes climate change and global warming. They trap the heat emitted by the earth and makes the environment warm. Some examples of other greenhouse gases are water vapour, Methane, Nitrous Oxide, Ozone etc.


Question 9.

The ________ form decomposers in the pond ecosystem.
A. plants

B. bacteria

C. frogs

D. phytoplanktons


Answer:

Bacteria and fungi form the decomposers in the pond. They decompose various organic substances produced by various organic activity in the pond.


Question 10.

_________ is used in seeding clouds.
A. potassium iodide

B. calcium carbonate

C. sulphurdioxide

D. ammonium phosphate


Answer:

Seeding clouds with dry ice or potassium iodide particles sometimes can initiate rain if the cloud is water laden.


Question 11.

An example for fossil fuel is _________ .
A. copper

B. iron

C. magnesium

D. coal


Answer:

Coal is a fossil fuel made of remains of dead plants and ferns over millions of year time duration due to decomposition, high temperature and pressure condition after its the deep burial beneath the subsurface of the earth.


Question 12.

Air pollution is caused by transport exhaust fumes and emission of gases like SO2, CO2, NO2 from industies. Similarly, water pollution is caused by ________ .
A. sewage

B. crop cultivation

C. rain

D. soil erosion


Answer:

Sewage water contains various unwanted material such as harmful chemicals, plastics etc. hence pollute water.


Question 13.

If wild animals are killed, what difficulty would we face?
A. imbalance in nature

B. decrease in fog rain

C. decrease in population

D. increase in rain


Answer:

If wild animals are killed, food chain will be altered so, it will affect every other living thing, and their survival will also go in dander.


Question 14.

Water is an essential commodity for survival. What can we do to help increase water resources?
A. deforestation

B. reducing the use of vehicles

C. the burning of the wastage

D. afforestation


Answer:

Planting trees would help in charging ground water as it checks the surface water flow and allows water more time to percolate through the soil to ground water. Trees are also helpful in making rainfall in a region.


Question 15.

The tiger and the lion are carnivores. Likewise, the elephant and the bison are_____________.


Answer:

Herbivores

Elephants eat grasses, small plants, bushes, twigs, fruit, tree bark, and roots etc. So, Elephants are herbivores. Bison eats grasses, sedges (a grass like plant), forbs (herbaceous flowering plant) etc. So, they are also herbivores.



Question 16.

Assertion (A): Coal and petroleum are called fossil fuels.

Reason (R): Fossil fuels are formed from the remains of dead organisms after millions of years.
A. Both ‘A’ and ‘R’ are true and ‘R’ explains ‘A’.

B. Both ‘A’ and ‘R’ are true and but ‘R’ doesn’t explain ‘A’

C. Only ‘A’ is true but ‘R’ is false.

D. ‘A’ is false but ‘R’ is true.


Answer:

Coal and Petroleum are formed from the remains of dead organisms after millions of years. So, both Assertion and Reasons are correct and Reason(R) explains Assertion(A).


Question 17.

Compressed Natural Gas (CNG) is considered a better fuel than coal/ petroleum, because _______.


Answer:

Compressed Natural Gas (CNG) is considered a better fuel than coal/ petroleum, because it is less polluting and produces fewer undesirable gases than the fossil fuels.



Question 18.

Now-a-days water bottles and lunch boxes are made from agricultural products like fruit pulp. These are called ______ .


Answer:

Bio-plastics

Bio-Plastics are Plastics made from plants including corn, potatoes or other agricultural products.



Part-b
Question 1.

Classify the following into producers, consumers, decomposers.

i) butterfly

ii) grass hopper

iii) calottes

iv) snakes

v) shoe flower

vi) nitrobacteria


Answer:


Plants are producers. So, shoe flower are producers. Butterfly, Grasshopper and Calottes are dependent on plant or their products. So, they are consumers. While several bacteria and fungi form the decomposers. So, nitrobacteria are decomposers.



Question 2.

Living organisms adapt themselves according to their habitat.

Match the following: -



Answer:

The correct matchings are as shown below:



Fishes live in water so adapt in it they have fins which helps them move in any desired direction and with optimum speed. The skin of the camel is doubly thick and contains water-storing osmotic cells to conserve water, as they live in deserts. Frogs have hind limbs with web which help them swimming in water and jumping over land. While birds have wing which helps them in flying from one place to another in search of food, water etc.



Question 3.

Fill in the blanks

i) Animals give out ________ through respiration.

ii) In the presence of sunlight, plants prepare ______.


Answer:

i) Animals give out carbon dioxide through respiration.


ii) In the presence of sunlight, plants prepare carbohydrate.



Question 4.

Bacteria and fungi are responsible for the decay of dead plants and animals. Decaying matter is recycled to grow plants. What do we call this?


Answer:

Bio-Geo chemical cycle.

Minerals are restored to the soil by the decomposition of dead and decaying materials by saprophytic organisms such as bacteria and fungi. This process is called Bio-Geo chemical cycle.



Question 5.

Fill in the blanks with suitable answers from those given in the brackets.

(harmful, heavy metals, carbon dioxide, sulphur particles)

Generation of waste products which contain Mercury, Uranium, Thorium, Arsenic, and other ________ are _______ to human health and environment. _______ present in the coal will cause acid rain and the release of _________, a greenhouse gas, causes climate change and global warming.


Answer:

Generation of waste products which contain Mercury, Uranium, Thorium, Arsenic, and other metals are harmful to human health and environment. sulphurparticles present in the coal will cause acid rain and the release of carbon dioxide, a greenhouse gas, causes climate change and global warming.



Question 6.

Depict a food chain by placing the following organisms in the correct trophic levels:

(snake, grass, eagle, frog, grasshopper)


Answer:

The correct order of food chain of given organisms is as given below:

Grass → Grasshopper → frog → snake → eagle


It says, grass will be eaten by grasshopper, grasshopper will be eaten by frog, frog will be eaten by snake and snake will be eaten by eagle.



Question 7.

Show an aquatic food chain using the following organisms.

(Small fish, Phytoplanktons, Kingfisher, Zooplanktons)


Answer:

Phytoplanktons → Zooplanktons → Small fish → Kingfisher



Question 8.

Observe the following food web:



(i) Find out the wrong statement:

a) ‘A’ is a producer

b) ‘F’ is a herbivore

c) ‘H’ is an omnivore

d) ‘I’ is a climax carnivore


Answer:

d) is the wrong statement.

We first divide the various organisms from bottom to top in various levels as shown below



Now, we see that organisms in the Level 1 are not shown to be dependent on any other organism. So, we can assume them to be producers or plants.


Level 2 organism are shown to be dependent on plants of Level 1. So, they are herbivores (or consumers).


At Level 3, the organisms are shown to consume either level 1 (plants) or level 2 (herbivores) or both organism. So, at Level 3 ‘H’ is omnivore and ‘I’ is carnivore.


At Level 4, the organism J is shown to consume level 2 (herbivores) as well as level 3 (omnivores) organisms. Implies J only eat animals. So, J is climax carnivore.



Question 9.

Observe the following food web:



Find out how many food chains are present in the above food web.


Answer:

There are ten food chain possible out of the given food web. They are as shown below:

(i) A → H → J


(ii) A → E → H → J


(iii) A → F → J


(iv) A → F → I → J


(v) B → F → J


(vi) B → F → I → J


(vii) C → G → I → J


(viii) C → G → J


(ix) D → G → I → J


(x) D → G → J



Question 10.

Observe the following Bio-geo chemical cycle.



i) Mention the nutrient in the given cycle.

ii) Write the activities from ‘A’ to ‘D’.


Answer:

(i) The nutrient in the given cycle is carbon.

(ii) The various activities taking place in the given cycle are:


A: Photosynthesis


Reasoning: Green plants take carbon dioxide from atmosphere for photosynthesis.


B: Respiration


Reasoning: Plants and animals exhale carbon dioxide during respiration process.


C: Combustion


Reasoning: Fuels need oxygen for their combustion, which they get from the atmosphere.


D: Decomposition


Reasoning: Micro-organisms decompose dead organisms and the gases produced so are released into the atmosphere.



Question 11.

Study the food chain below, correct it and convert it into a pyramid of energy.

Mulberry → Sparrow → Caterpillar → Kite


Answer:

Energy flow from producers towards consumers of different levels in the food chain. The corrected food chain is as given below:

Mulberry → Caterpillar → Sparrow → Kite


The equivalent energy pyramid is as shown below:




Question 12.

Study the illustration and answer the questions:

i) Which line (A or B) represents the flow of energy?

Why do you say so?

ii) Give an example of a decomposer.



Answer:

(i) Line B represents the flow of energy.

Reason: The energy flow in a food chain is unidirectional and from producers to consumer. The reverse is not possible, but the line A represents a cyclic flow. So, line A cannot represent energy flow.


(ii) Fungi and bacteria are examples of decomposer.



Question 13.

i) Name the processes noted as No. 1 and 3.

ii) Define process 1.



Answer:

(i) Process 1 represents Photosynthesis and Process 2 represents respiration

Reason:


In process 1 as shown in the figure, green plant is taking carbon dioxide from the atmosphere, which is nothing but an event of photosynthesis. While in process 2 animal is releasing carbon dioxide into the atmosphere in the process of respiration.


(ii) Process 1 is photosynthesis. Photosynthesis is defined as the process by which green plants synthesise their food by taking carbon dioxide from air and water from ground in the presence of sunlight.



Part-c
Question 1.

i) Classify the following substances – wood, paper, plastic and grass.

ii) Give a detailed account of your classification.


Answer:

(i) The given substances can be classified as biodegradable and non-biodegradable as shown below: Biodegradable : wood, paper and grass non-Biodegradable : Plastic


(ii) Substances which can be broken down by biological processes or microbial action are known as Biodegradable. Wood, paper, leaves, cotton etc. are some examples of biodegradable substances. While substances which are not broken down by biological processes or microbial action are known as Non-biodegradable. Plastic, cans, tyres, paints etc. are some examples of Non-biodegradable substances.



Question 2.

In your locality people are affected due to water scarcity. What measures will you take to deal with the problem of water scarcity?


Answer:

In the case of water scarcity, I will take the following measures to deal with the situation:

(i) Always keep the water filled container covered in order to prevent any evaporation.


(ii) For washing vehicles, I’ll use recycled water.


(iii) For gardening I will use water which was used to wash vegetables.


(iv) I will harvest rain water by making tank in the yard and connecting it to the roof trough pipelines.


(v) I will persuade authority to install a small reverse osmosis plant to purify water of river or ocean to meet the need of water.


(vi) Using every drop of water very carefully and not wasting it.



Question 3.

We are surrounded by smoke. Is this situation good for our health? Give reason.


Answer:

No, this situation is not good for our health.

Reasons:


1. Smoke content above a particular level can causes allergy and irritation to the eyes and throat. High smoke content in air can also cause upper respiratory infections such as bronchitis and pneumonia.


2. Some contains pollutants. When air containing such pollutants are inhaled may lead to serious health problems affecting the functioning of lungs and the respiratory system.


3. Smoke causes serious respiratory diseases, heart disease, stroke and lung cancer etc.


4. Smoke leads to difficulty in breathing, wheezing, coughing, asthma and worsening of existing respiratory and cardiac diseases.



Question 4.

List out the harmful effects of burning coal.


Answer:

Harmful effects of burning coal are as given below:

(1) Burning coal releases carbon dioxide in air, which is a greenhouse gas and leads to global warming.


(2) Coal burning also releases oxides of sulphur in air, which contribute to the process of Acid rain.


(3) The smoke from burning coal leads to increased unwanted particulate matter in the environments leading to air pollution.


(4) Harmful metals such as mercury, lead and arsenic are also released into environment from burning of coal, which when inhaled can lead to serious health problems such as damage of nervous system, immune system and digestive system. It is a serious threat to the development of a child.