Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

   

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Tamilnadu Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

Samacheer Kalvi 6th Science Our Environment Textual Evaluation

I. Choose the appropriate answer :

Question 1.
Identify the fresh water ecosystem.
(a) Pond
(b) Lake
(c) River
(d) All of them
Answer:
(d) All of them

Question 2.
Producers are
a. Animals
b. Birds
c. Plants
d. Snakes
Answer:
c. Plants

Question 3.
It is a biodegradable waste
(a) Plastic
(b) Coconut Shell
(c) Glass
(d) Aluminium
Answer:
(b) Coconut shell

Question 4.
It is an undesirable change that occurs in air and water.
a. Recycling
b. Reuse
c. Pollution
d. Reduce
Answer:
c. Pollution

Question 5.
Usages of chemical pesticides and fertilisers causes pollution.
(a) Air pollution
(b) Water pollution
(c) Noise pollution
(d) None of the above
Answer:
(b) Water pollution

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

II. Fill in the blanks :

  1. Primary consumers that eat plants are called _______
  2. Temperature, light and wind are _______ factors.
  3. _______ is the process of converting waste materials into new materials.
  4. Water pollution can spread _______ and chemicals.
  5. The 3R’s are Reduce, _______ and Recycle.

Answers:

  1. Herbivores
  2. Physical
  3. Recycling
  4. Diseases
  5. Reuse

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

III. True or False. If False, give the correct statement :

Question 1.
The Pacific ocean is an example of an aquatic ecosystem.
Answer:
True.

Question 2.
Bacteria and fungi are called decomposers.
Answer:
True.

Question 3.
Human and animal wastes are examples of non-biodegradable waste.
Answer:
False. Human and animal wastes are examples of biodegradable waste.

Question 4.
Excessive use of pesticides leads to air pollution.
Answer:
False. Excessive use of pestides leads to water pollution.

Question 5.
In schools, waste management rules say that we should separate waste in two categories.
Answer:
True

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

IV. Match the following :

Question 1.

  1. Biotic factor – Terrestrial Ecosystem
  2. Sewage – Land pollution
  3. Fertilizers – Air pollution
  4. Desert – Water Pollution
  5. Smoke – Animals

Answer:

  1. Biotic factor – Animals
  2. Sewage – Water pollution
  3. Fertilizers – Land pollution
  4. Desert – Terrestrial ecosystem
  5. Smoke – Air pollution

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

V. Arrange the following in a correct sequence and form a food chain

Question 1.
Rabbit → Carrot → Eagle → Snake
Answer:
Carrot → Rabbit → Snake → Eagle

Question 2.
Human → Insect → Algae → Fish
Answer:
Algae → Insect → Fish → Human

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

VI. Give Very Short Answer:

Question 1.
Define ecosystem.
Answer:
An ecosystem is a community of living or biotic and non-living or a biotic things that work together.

Question 2.
What are the two types of ecosystems?
Answer:
Types of ecosystems :

  1. Natural ecosystem
  2. Artificial ecosystem

Question 3.
Write any two things that can be recycled.
Answer:
Examples :

  1. Old clothes
  2. Plastics

Question 4.
What are the types of pollution?
Answer:
There are four major kinds of pollution :

  1. Air Pollution.
  2. Water Pollution.
  3. Land (Soil) Pollution.
  4. Noise Pollution.

Question 5.
Give one example of a food chain in an aquatic ecosystem.
Answer:
Food chain in aquatic ecosystem.
Aquatic plant → Aquatic insect → Larva → Fish.

Question 6.
Name some pollutants.
Answer:

  1. Toxic gases and fine particles from burning fossil fuels, chemicals released from factories.
  2. Sewage, industrial effluents, pesticides and fertilizers
  3. Plastics and electronics are land pollutants.

Question 7.
What are the pollutions caused by the objects given below?
a. Loud Speaker
b. Plastic
Answer:
a. Loud Speaker – Noise Pollution.
b. Plastic – Land Pollution.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

VII. Give Short Answer:

Question 1.
What is biodegradable waste?
Answer:
The term ‘‘Biodegradable” is used for those things that can be easily decomposed by natural agents like water, oxygen, ultraviolet rays of sun and microorganisms etc.

Question 2.
How can we reduce water pollution?
Answer:

  1. Do not pour leftover oil, old medicines or waste down the drain or into the toilet.
  2. Reduce the use of chemical pesticides and fertilizers to grow crops.
  3. Reduce the use of detergents and bleach to wash clothes.
  4. Do not litter or dump waste always use a waste bin.

Question 3.
Write the importance of the food chain.
Answer:
Importance of food chain

  1. Learning food chain help us to understand the feeding relationship and interaction between organisms in any ecosystem.
  2. Understanding the food chain also helps us to appreciate the energy flow and nutrient circulation in an ecosystem.
  3. This is important because pollution impacts the ecosystem. The food chain can be used to understand the movement of toxic substances and their impacts.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

VIII. Answer in detail:

Question 1.
Give two examples of how you can avoid or reduce waste?
Answer:
Examples of how we can Avoid waste:-
Avoid buying packaged foods. Refuse to buy ‘use-and-throw’ plastic products.

Examples of how we can Reduce waste:-

  1. Write on both sides on paper
  2. Share newspaper and magazines with others.

Question 2.
Write a short note on noise pollution.
Answer:

  1. Noise pollution is caused by loud sounds.
  2. Loud music, the sounds of motor vehicles, fireworks and machines cause noise pollution which affects the environment.
  3. We all like a quiet and peaceful place since unpleasant or loud sounds disturb us.
  4. Continuous noise disturbs our sleep and does not let us study.
  5. It leads to stress and health impacts such as high blood pressure and hearing loss.
  6. Loud noise or music can damage our ears.
  7. It also disturbs animals. For example in noisy areas birds have to communicate louder so they can hear each other.
  8. Even underwater noise pollution from ships can make whales lose their way as they use sounds to navigate.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

IX. Questions based on Higher Order Thinking Skills :

Question 1.
What would happen if an organism is removed from the food chain?
Answer:
If an organism is removed from the food chain,

  1. The food chain will fall apart.
  2. The ecosystem will become imbalance and collapse.
  3. For example, Consider a food chain: Plants → grasshoppers → frogs → snakes → hawks.

If frogs were to die off in this chain, (due to disease/pollutants), then, there will be an increase in the number of grasshoppers. This will cause a major problem.

Question 2.
Explain the link between waste and dangerous diseases like dengue and malaria?
Answer:

  1. Dengue and malaria fever are caused by the bite of mosquitoes.
  2. Accumulation of waste and stagnant water or uncovered containers of stored drinking water are the habitat for breeding mosquitoes.
  3. In order to control these infectious diseases, people should maintain clean environment, free from mosquitoes.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

X. See the diagram and answer the following questions :

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 1

Question 1.
Explain what is happening in the picture?
Answer:

  1. The atmosphere is polluted in this picture. It is due to the smoke arising from burning garbage.
  2. Land and water have been polluted because of leaching the toxins into the soil and water.

Questions 2.
What types of pollution are caused by open dumps?
Answer:
The following types of pollution are caused by open dumps :-

  1. Water pollution
  2. Land pollution
  3. Air pollution

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

Samacheer Kalvi 6th Science Our Environment Intext Activities

Activity 1

Question 1.
Think of the objects in your home. Just keep in mind, the books, toys, furniture, food materials and even pets of your home. These living and non-living things together make your home. Look at the following picture and list out the living and non-living things.
Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 2
Answer:
Living things : Plants, Beetle, Mosquito, Larva, Water snake, Water scorpion, Snail, Fish, Duck and Frog etc.
Non- living things : Sun, Air, Water, Chemicals, Soil, Rocks and Temperature etc.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

Activity 2

Take a square paper. Fold its diagonals. Draw three lines in three triangles as shown in the picture.

Cut from the edge of the diagonal to the centre as shown in the picture.
Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 3
If you fold this triangle and paste behind the third triangle you get a pyramidal shape.

In one of the triangles, draw images of each of the organisms in the different levels.

In another triangle write the names of the organisms. In the last triangle, write the energy level of the organism. Have a look at the following example. You must come up with different organisms!

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 4

Answer:
Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 5

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

Activity 3

Take two mud pots or glass jars and fill them up with garden soil. In the first pot, mix wastes such as banana peel, some vegetable peels and a few tree leaves into the soil. In the second pot, mix a piece of plastic carry bag, sweet wrapper and metal foil into the soil.

What happen to the waste materials placed in both pots? Do you notice a difference between first and second pot? Observe the changes over two weeks and discuss with your classmates.
Answer:
After two weeks, the wastes in the first pot, such as banana peel, some vegetable peel and tree leaves are degraded.

The wastes in the second pot such as carry bag, sweet wrapper and metal foil are not degraded.

Because, the first pot has biodegradable wastes. So they are degraded. But the second pot has non-biodegradable wastes. So they are not degraded.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

Activity Pg.No : 53

Question 1.
Give some examples for Biodegradable and non-biodegradable waste.
Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 6
Answer:
Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 7

Activity 4

Question 1.
Preparation of Vermi Compost
Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 8

  1. Dig a pit for about one feet depth in the backyard or garden of your home or school.
  2. Fill the pit by bio-wastes, paper and food wastes, place few earth worms in it, sprinkle water and close the place with jute or cardboard and ensure moisture all the time.
  3. After 45 days the vermi casting layer formed just above the pit.
  4. These castings will be applied to the plant.
  5. This contains water soluble nutrients.
  6. This type of compost helps in plant growth as well as sustain the land is fertility.

Answer:
Activity to be done by the students themselves

Classroom Exercise:
Identify who am I ?

Question 1.
I am the type of pollution caused by burning of fossil fuels like pertrol (or) coal and the smoke of burning garbage. I float around and cause breathing problems. I am _______ pollution.
Answer:
Air.

Question 2.
I am the type of pollution caused by loud sounds and I can cause serious damage to your ears and also affect sleep. In India, I am mainly caused by loudspeakers and honking of air horns of cars. I am _______ pollution.
Answer:
Noise.

Question 3.
I flow from homes and farms into rivers and lakes. I kill fish and make water unfit for drinking. I am _______ pollution.
Answer:
Water.

Question 4.
I am the type of pollution caused by using too much chemical fertilizers and pesticides by farmers. I lower the quality of soil and even move chemicals into plant parts which are eaten by people. I am _______ pollution.
Answer:
Land.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

Samacheer Kalvi 6th Science Our Environment Additional Questions

I. Choose the appropriate answer:

Question 1.
These are abiotic factors.
i. Sunlight
ii. Bacteria
iii. Air
iv. Plants
(a) i and ii
(b) i and iii
(c) ii and iv
(d) iii and iv
Answer:
(b) i and iii

Question 2.
Pick out the terrestrial ecosystem
(a) lake
(b) mountain regions
(c) deserts
(d) both b and c
Answer:
(d) both b and c – mountain regions deserts

Question 3.
_______ are organisms that are able to produce their own Organic food.
(a) Producers
(b) Consumers
(c) Decomposer
(d) Omnivores
Answer:
(a) Producers

Question 4.
The primary energy production in the world of living things is made by?
(a) aquatic insect
(b) rabbit
(c) plants
(d) deer
Answer:
(c) plants

Question 5.
Natural agents like _______ are the decomposition factors breaking complex forms to simpler unit.
(a) Oxygen
(b) Water
(c) micro organisms
(d) All the above
Answer:
(d) All the above

Question 6.
The average person in India produces _______ kg of waste everyday
(a) 0.45
(d) 055
(c) 0.40
(d) 0.55
Answer:
(a) 0.45

Question 7.
Most _______ pollution is caused by the burning these fossil fuels.
(a) Water
(b) Land
(c) Air
(d) Noise
Answer:
(c) Air

Question 8.
Among the following which one is not polluted by noise pollution?
(a) Sounds of motor vehicles
(b) Music from radio
(c) Firing crackers
(d) Loud music
Answer:
(b) Music from radio

Question 9.
_______ Pollution has been directly linked to stress and health impacts such as high blood pressure and hearing loss.
(a) Noise
(b) Land
(c) Water
(d) Air
Answer:
(a) Noise

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

II. Fill in the blanks:

  1. _______ are called as biotic factors.
  2. _______ is the best example of natural terrestrial ecosystem.
  3. Ecosystem originated without human intervention is called _______
  4. The ecosystem in water is called _______ ecosystem.
  5. _______ obtained energy from the chemical breakdown of dead organisms.
  6. The sequence of who eats whom in an ecosystem is called as _______
  7. The food chain begins with the energy given by the _______
  8. Each level in the food chain is called a _______ level.
  9. The burning of solid waste in _______ is called incineration.
  10. Garbage buried inside landfills remain here for a long time as they decompose very slowly and become _______
  11. Polluted _______ affects skin, eyes and respiratory system.
  12. Land (Soil) pollution happens when toxic change the natural balance in soil.

Answers:

  1. Plants
  2. Forest
  3. Natural ecosystem
  4. Aquatic
  5. Bacterium
  6. Food chain
  7. Sun
  8. Trophic
  9. Incinerator
  10. Manure
  11. Air
  12. Chemicals

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

III. True or False. If False, give the correct statement:

Question 1.
Forest and Mountain regions are the best examples of the artificial terrestrial ecosystem.
Answer:
False. Forest and Mountain regions are the best examples of the natural terrestrial ecosystem.

Question 2.
Fish and other water creatures and plants are maintained in the terrarium.
Answer:
False. Fish and other water creatures and plants are maintained in the aquarium.

Question 3.
Animals that eat both plants and animals are called as Carnivores.
Answer:
False. Animals that eat both plants and animals are called as Omnivores.

Question 4.
In a food chain grasshopper gets energy by eating frog.
Answer:
False. In a food chain frog gets energy by eating grasshopper.

Question 5.
If we protect the ecosystem, we can reduce waste by using durable goods.
Answer:
True.

Question 6.
The term non-biodegradable is used for those things that can be easily decomposed.
Answer:
False. The term non-biodegradable is used for those things that cannot be easily decomposed.

Question 7.
The process by which waste materials are used to make new products is called recycling.
Answer:
True.

Question 8.
Expired medicines, used batteries are domestic hazardous waste.
Answer:
True.

Question 9.
Lcrud noise or even loud music can damage our eyes.
Answer:
False. Loud noise or even loud music can damage our ears.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

IV. Match the following :

A.

i. Abiotic factor (a) Deer
ii. Decomposers (b) Owl
iii. Herbivores (c) Heat
iv. Carnivores (d) Human
v. Omnivores (e) Fungi

Answers:
i – c
ii – e
iii – a
iv – b
v – d.

B.

i. Avoid the usage (a) Recycle
ii. Sharing newspapers (b) Incinerate
iii. Using of fountain pens (c) Buying packaged food
iv. Using old clothes to make paper (d) Reducing
v. Human anatomical waste (e) Reusing

Answers:
i – c
ii – d
iii – e
iv – a
v – b.

C.

i. Burning coal (a) Land pollution
ii. Throwing plastic (b) Noise pollution
iii. Waste water from factories is mixed with river (c) Air pollution
iv. Louder hom of vehicle (d) Water pollution

Answers:
i – c
ii – a
iii – d
iv – b.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

V. Analogy:

Question 1.
Biotic factor : Animals :: Abiotic factor : _______
Answer:
Air or Water.

Question 2.
Natural terrestrial ecosystem : Forest:: Artificial terrestrial ecosystem : _______
Answer:
Garden.

Question 3.
Primary Consumer : Goat, Cow :: Secondary Consumer : _______
Answer:
Frog, Owl.

Question 4.
Biodegradable waste: Leaves, Garden wastes:: Non-biodegradable waste: _______
Answer:
Plastic cover, glass bottle.

Question 5.
Edaphic factor : Water in soil:: Physical factor : _______
Answer:
Light.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

VI. Give Short Answer:

Question 1.
List out the following by biotic and abiotic factors. (Sun, plants, animals, air, soil, bacteria, heat, minerals.
Answer:
Abiotic Factors:
Sun, Air
Water, Soil
Heat, Minerals

Biotic Factors:
Plants
Animals
Bacteria

Question 2.
Give a brief account on land fill.
Answer:

  1. Land filing is a method in which wastes are dumped into naturally occurring or man-made pits and covered with soil.
  2. Garbage buried inside landfills remains here for a long time as they decompose very slowly and become man use.
  3. These places can be converted into parks, gardens etc.
  4. The first step should always be to reduce waste.
  5. The second step is to keep waste separate. So that the waste can be easily reused or recycled.

Question 3.
Define – Aquarium.
Answer:
An aquarium is a place in which fish and other water creatures and plants are maintained. Example : Fish growing in homes with small tank.

Question 4.
What is Autotrophs?
Answer:
Producers are organisms that are able to produce their own organic food. They do not need to eat other organisms, to do this. Producers are also called Autotrophs.

Question 5.
Define – Heterotrophs.
Answer:
Organisms which cannot produce their own food, need to eat other organisms as food. These Organisms are also called consumers. All animals are consumers as they cannot produce their own food. Consumers are also called Heterotrophs.

Question 6.
Differentiate between herbivores and carnivores.
Answer:
Herbivores:

  1. Animals which eat plants or plant products.
  2. Ex : Deer, Goat, Cattle and Rat.

Carnivores:

  1. Animals that eat other animals..
  2. Ex : Lion, Tiger, Frog and Owl.

Question 7.
What are decomposers?
Answer:
Micro-organisms (both plants and animals) that obtain energy from the chemical breakdown of dead organisms. They break complex organic substances into simple organic substances that goes into the soil and are used by plants.

Example : Bacterium, Fungi.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

Question 8.
Define – Food web.
Answer:

  1. If we put all the food chains within an ecosystem together, then we end up with many interconnected food chains. This is called as food web.
  2. A food web is very useful to show the many different feeding relationships between different species within an ecosystem.

Question 9.
What is reuse? Give examples.
Answer:
Reusing means using a thing again and again, rather than using and throwing after a single use.

Example :

  1. Instead of using plastic bags, use cloth bags.
  2. Rechargeable batteries and fountain pens.

Question 10.
What is Landfill?
Answer:
Landfilling is a method in which wastes are dumped into naturally occuring (or) man-made pits and covered with soil.

Question 11.
Give the Solid Waste Management (SWM) rules.
Answer:
The Solid Waste Management (SWM) rules, 2016, say that,

i. Every lTousehold should segregate and store the waste generated by them in three separate streams namely bio-degradable, non-bio-degradable and domestic hazardous waste in suitable bins and handover the segregated wastes to authorised waste pickers, (or) waste collector as per direction or notification by the local authorities from time to time.

ii. Nobody shall throw, bum, or bury the solid waste on streets, open public spaces outside his premises or in the drain or water bodies.

Question 12.
List any four domestic hazardous waste.
Answer:

  1. Discarded paint drums
  2. Pesticide cans,
  3. CFL bulbs, tube lights
  4. Used batteries, used needles and syringes.

Question 13.
How can we reduce land pollution?
Answer:

  1. First try to reduce waste, then recycle the rest.
  2. Always use a waste bin and never litter.
  3. Do not bum waste, the ash mixes easily with soil.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

VII. Answer in detail:

Question 1.
Give the types of ecosystem by flow chart.
Answer:
Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment 9

Question 2.
How can we reduce air pollution?
Answer:

  1. Cycle or walk short distances instead of using a motor vehicle.
  2. Travel by public transport (bus or train)
  3. Do not burn solid waste.
  4. Avoid fireworks.

Samacheer Kalvi 6th Science Solutions Term 3 Chapter 4 Our Environment

Question 3.
Classify the most significant sources of water pollutants.
Answer:
The most significant sources of water pollutants are:

  1. Sewage (water we use at home for bathing, cleaning, cooking).
  2. Industrial effluents (liquid wastes from factories).
  3. Agricultural pollutants (chemical pesticides and fertilisers that get washed from farms).
  4. Solid waste (when waste gets dumped into water bodies).

Question 4.
How do we reduce noise pollution?
Answer:

  1. Turn off your electronics when you do not use them.
  2. Lower the volume when you watch TV or listen to music.
  3. Remind drivers not to use the horn too much.
  4. Avoid fireworks.
  5. Speak, do not shout (try to set an example).