Samacheer Kalvi 9th Social Science Geography Solutions Chapter 5 Pdf

Samacheer Kalvi 9th Social Science Geography Solutions Chapter 5 Pdf

Tamilnadu Board Samacheer Kalvi 9th Social Science Geography Solutions Chapter 5: Tamilnadu State Board Solution Class 9 Social Science Geography Chapter 5 – Biosphere.

Samacheer Kalvi 9th Social Science Geography Solutions Chapter 5: Overview


Samacheer Kalvi



Social Science (Geography)


Chapter Name


Samacheer Kalvi 9th Social Science Geography Solutions Chapter 5 Biosphere

I.) Choose the correct answer

1.) The coldest biome on Earth is Tundra.

a) Tundra

b) Taiga

c) Desert

d) Oceans

2.) This is the smallest unit of biosphere. : Ecosystems

a) Ecosystems

b) Biome

c) Environment

d) None of the above

3.) Nutrients are recycled in the atmosphere with the help of certain micro-organisms, referred to asNone of the above.

a) Producers

b) Decomposers

c) Consumers

d) None of the above

4.) To which climatic conditions are Xerophytic plants specifically adapted to? : Saline and sandy

a) Saline and sandy

b) Limited moisture availability

c) Cold temperature

d) Humid

5.) Why is the usage of rainforest biomes for large scale agriculture unsustainable? : because the soil is poor.

a) because it is too wet.

b) because the temperature is too warm.

c) because the soil is too thin.

d) because the soil is poor.

II.) Assertion type questions.


a) Both assertion (A) and reason(R) are true; R explains A

b) Both assertion(A) and reason(R) are true; R does not explain A

c) A is true; R is false

d) Both A and R are false

1.) A: Heterotrophs do not produce their own food.

R: They depend on autotrophs for their nourishment.

Answer:a) Both assertion (A) and reason(R) are true; R explains A

2.) A: Hotspots are the regions characterised by numerous endemic plants and animal species living in a vulnerable environment.

R: To manage and focus on conservation work more effectively, researchers identified hotspots.

Answer: a) Both assertion (A) and reason(R) are true; R explains A

III.) Fill In The Blanks

1.) An area where animals, plants and micro-organisms live and interact with one another is known as Ecosystem.

2.) Consumers are also called Heterotrophs.

3.) Food web is a system of interlocking and independent food chains.

4.) A Biome is an extensive large ecosystem.

5.) The vegetative type commonly found in desert biomes is called Xerophytes.

6.) Estuary is an aquatic biome that is found where fresh water and salt water mix.

IV.) Answer the following in brief

1.) What is Biosphere?

Answer: Biosphere is the fourth layer of the earth. It is the layer where life exists. This layer supports organisms. This layer comprises lithosphere, hydrosphere and atmosphere. Flora and fauna are the part of this layer.

2.) What is an ecosystem?

Answer: When all living organisms live and interact with each other and also interact with on-living environment like land, soil, air, water etc. this system is known as Ecosystem.

3.) What does the term ‘biodiversity’ mean?

Answer: Biodiversity means a wide variety of living organisms like plants, animals and other micro-organisms.

4.) What is meant by loss of biodiversity?

Answer:  Due to human activities or natural processes some species extinguishes, it known as loss of biodiversity.

5.) Mention the various terrestrial biomes.

Answer: Various terrestrial biomes are

i) Tropical Forest Biomes

ii) Tropical Savanna Biomes

iii) Desert Biomes

iv) Temperate Grassland Biomes

v) Tundra Biomes

V.) Give reasons for the following

1.) Producers are also called autotrophs.

Answer: Producers are also called autotrophs because they are self-nourishing component of the ecosystem.

2.) Biosphere provides a stable ecosystem.

Answer: Biosphere provides a stable ecosystem because, clean and pure water, enriched soil, food, raw materials, medicines etc. are provided by biosphere and healthy ecosystem conserved.

VI.) Distinguish between the following

1.) Producers and Decomposers.


Producers Decomposers
Producers are self-nourishing components of the ecosystem. Decomposers are some organisms that are incapable of preparing its own food.
Producers are self-nourished hence they are called Autotrophs. Decomposers are live on dead and decaying plants and animals hence they are called Saprotrophs.
Examples: Plants, Algae, Bacteria etc. Examples: Fungus, Mushrooms etc.

2.) Terrestrial biomes and Aquatic biomes.


Terrestrial Biomes Aquatic Biomes
Terrestrial biomes are group of living organisms that live and interact with one another on land. Aquatic Biomes are group of living organisms that live and interact with one another and its aquatic environment for nutrients and shelter.
Terrestrial Biomes are determined by temperature and rainfall. Aquatic biomes are influenced by a series of abiotic factors.
Classified as Tropical Forest biomes, tropical savanna biomes, desert biomes, temperate, grassland biomes, tundra biomes. Classified as fresh water biomes and marine biomes.

3.) Tropical vegetation and Desert vegetation


Tropical vegetation Desert vegetation
Tropical forest biomes comprised many sub-biomes like evergreen rainforest, seasonal deciduous forest etc. Dessert vegetation is found in the western margins of the continents.
Occupation of the people in this region is fishing, lumbering and shifting cultivation. Main occupation of the people is slaughtering of animals, packing of raw and processed meat, dairy products etc.
Animals like Bats, pheasants, jaguars, elephants, monkeys are found here. Grasshopper, wolf, bison, prairie dog etc are common birds and animals.

4.) Savannas and Tundra


Savannas Tundra
Tropical Savanna found between tropical forests and deserts. Between 10O to 20O North and South latitudes. Tundra is found where ground remains frozen.
Savannas found in the Sahel, south of Sahara in East Africa and in Australia. Greenland, Arctic and Antarctic regions and Northern parts of Asia, Canada and Europe fall in this biome.
Savanna biomes are generally hot and dry and have moderate to low rainfall. This region has long severe winter and short cool summer.
Main occupation of the people in this biome is herding. Fishing and hunting are main occupation in this biome.
Lion, leopard, tiger, deer, zebra, giraffe are found in this region. Polar bear, wolverine, reindeer, snowy owl are found in this biome.

VII.) Answer the following in a paragraph

1.) Explain the various components of ecosystem.

Answer: There are three basic components of ecosystem.

i) Abiotic components

ii) Biotic components

iii) Energy components

i) Abiotic components: This component has non-living, inorganic, physical and chemical factors in the environment. For example, land, air, water etc are abiotic components of the ecosystem.

ii) Biotic components: Biotic components means plants, animals and micro-organisms are involved in it. Biotic components are divided in three categories.

a) Producers: Producers are self-nourishing hence they are known as Autotrophs. Producers found on land and in the water. Plants, algae, bacteria are some of the examples of the producers.

b) Consumer: Consumer means the organisms directly or indirectly depended on the producers; hence they are known as Heterotrophs. Consumers also divided into three categories.

  • Primary Consumers: There consumers are depending on the producers for food. And mainly herbivores like zebra, goat etc.
  • Secondary consumers: Secondary consumers are small carnivores it means they consume herbivores like lion, snake etc.
  • Tertiary consumers: These are top carnivores, prey on herbivores and carnivores both. Like owl, crocodile etc.

c) Decomposers: Decomposers are some organisms who unable to prepare their own food so they live on dead and decaying plants and animals. Hence, they are known as Saprotrophs. Like fungus, mushrooms etc.

2.) Write a paragraph on the functions of an ecosystem.

Answer: The living organisms interact with each other and make different levels, food chains and food webs. The pattern of the energy flow determines the functioning of an ecosystem. Energy flow helps to distribute and circulate the organic and inorganic matter within an ecosystem. Energy flow takes place in hierarchical order generally through many levels, known as trophic levels.

When energy transform from one group of organisms to another group of organisms is known through many trophic levels is known as food chain and a system of interlocking and interdependent food chains is known as food web.

3.) Explain about the aquatic biomes on Earth.

Answer: Aquatic biomes is described as a group of living organisms that live and interact with each other in the aquatic environment for nutrients and shelter. Aquatic biomes are influenced by a series of abiotic factors. Aquatic biomes divided in two categories fresh water biomes and marine biomes.

i) Fresh water biomes: Fresh water biomes means lakes, ponds, rivers, streams, wetlands etc. Fresh water biomes is influenced by various abiotic components like volume of water, water flow, composition of oxygen, temperature, etc. For drinking water, crop irrigation, sanitation and industry we human depended on fresh water. Common plants grow in fresh water are water lily, lotus, duck weeds etc.

ii) Marine biomes: Marine biomes is largest aquatic biomes on the earth. Marine biomes are continuous salted water with wide range for marine plants and animals. Within the ocean, Coral reefs are a second kind of marine biomes. At some places salt water and fresh water mixes this type of place is known as estuaries. Estuaries also forms unique marine biome. As water flow, marine organisms, nutrients are get circulated with the flow in estuaries. Along with animals, other plants like kelp, algae, phytoplankton etc grow in water. Aquatic biomes are important for humans also. Humans are dependent on aquatic biomes for water, food and leisure activities but overfishing, pollution and rise in the sea level are some of the threats for aquatic biomes.


1.) World Wild Life Day 3rd March.

2.) International Day of Forest 21st March.

3.) World Water Day22nd March.

4.) Earth Day 22nd April.

5.) World Environment Day 5thJune.

6.) World Oceans Day 8th June.

Updated: July 20, 2021 — 11:02 pm

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