Text Book Back Questions and Answers - Chapter 5 Biosphere 9th Social Geography Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

Updated On May 15, 2024

By SaraNextGen

Chapter 5 - Biosphere - 9th Social Geography Guide Samacheer Kalvi Solutions  - Text Book Back Questions and Answers

I. Fill in the blanks.
1. An area where animals, plants and micro organisms live and interact with one another is known as ______
2. ......... are also called Heterotrophs.
3. ....... is a system of interlocking and independent food chains.
4. .......... is an extensive large ecosystem.
5. The vegetative type commonly found in desert biomes is called .....
6. ....... is an aquatic biome that is found where fresh water and salt water mix.

Answers:
1. Habitat
2. Consumers
3. Food web
4. A biome
5. Xerophytes
6. Estuary
II. Choose the correct answer.

Question 1.
The coldest biome on Earth is
(a) Tundra
(b) Taiga
(c) Desert
(d) Oceans

Answer:
(a) Tundra

Question 2.
This is the smallest unit of biosphere.
(a) Ecosystems
(b) Biome

(c) Environment
(d) None of the above

Answer:
(a) Ecosystems

Question 3.
Nutrients are recycled in the atmosphere with the help of certain micro organisms, referred to as
(a) Producers
(b) Decomposers
(c) Consumers
(d) None of the above

Answer:
(b) Decomposers

Question 4.
To which climatic conditions are Xerophytic plants specifically adapted to?
(a) Saline and sandy
(b) Limited moisture availability
(c) Cold temperature
(d) Humid

Answer:
(a) Saline and sandy

Question 5.
Why is the usage of rainforest biomes for large scale agriculture unsustainable?
(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

Answer:
(b) because the temperature is too warm

Questions 6-8 are assertion type questions.
Directions:
(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 $\mathrm{A}$ and $\mathrm{R}$ are false

Answer:
(C) A is true; $R$ is false

Question 6.
(A): Heterotrophs do not produce their own food.
(R): They depend on autotrophs for their nourishment.

Answer:
(C) $A$ is true; $R$ is false

Question 7.
(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; $\mathrm{R}$ explains A

Question 8.
(A): The number of gorillas in Africa has plummeted by $60 \%$ in the past twenty years.
(R): Non intervention of human beings in the forest areas.

Answer:
(D) Both $\mathrm{A}$ and $\mathrm{R}$ are false
III. Answer the following in brief:

Question 1.
What is Biosphere?
Answer:
Biosphere is a life supporting layer that exists on the earth's surface. This layer on earth encompasses the Lithosphere, Hydrosphere and Atmosphere. It includes flora and fauna that thrive on or near the earth's surface.

Question 2.
What is an ecosystem?
Answer:
The place on earth where living organisms live and interact with one another and with their physical environment is called an ecosystem.

Question 3.
What does the term 'biodiversity' meant
Answer:
Biodiversity or biological diversity refers to a wide variety of living organisms (plants, animals and other micro organisms) which live in a habitat. It is highly influenced by topography, climate as well as human activities.

Question 4.
What is meant by loss of biodiversity?
Answer:
The extinction of species (flora and fauna) due to human and natural influences is called
loss of biodiversity. The biodiversity loss has a great impact on mankind and also affects land, water, air etc. Habitat destruction due to deforestation, population explosion, pollution and global warming are the major cause for loss of biodiversity.

Question 5.
Mention the various terrestrial biomes.
Answer:
The major terrestrial biomes of the world are:
A. Tropical Forest Biomes
B. Tropical Savanna Biomes
C. Desert Biomes
D. Temperate Grassland Biomes
E. Tundra Biomes

IV. Distinguish between the following:

Question 1.
Producers and Decomposers.
Answer:

Question 2.
Terrestrial biomes and Aquatic biomes

Answer:

Question 3.
Tropical vegetation and Desert vegetation

Answer:

Question 4.
Savannas and Tundra
Answer:

V. Give reasons for the following:

Question 1.
Producers are also called autotrophs.
Answer:
Producers are self nourishing components of the ecosystem. Hence they are called Autotrophs. They are found both on land and water, e.g. Plants, Algae, Bacteria etc.

Question 2.
Biosphere provides a stable ecosystem.
Answer:
1. Biosphere extends from the deep ocean trenches to lush rain forests.
2. People play an important role in maintaining the flow of energy in the biosphere.
3. There are places on earth that are both biologically rich and deeply threatened.
4. Hence Biosphere provides a stable ecosystem.
VI. Answer the following in a paragraph:

Question 1.
Explain the various components of ecosystem.
Answer:
An ecosystem is a community, where all living organisms live and interact with one another and also with their non-living environment such as land, soil, air, water etc.
Ecosystems range in size from the smallest units (e.g. bark of a tree) that can sustain life to the global ecosystem or ecosphere. (e.g. Cropland, Pond ecosystem, Forest ecosystem, Desert ecosystem etc.). Biosphere harbours all ecosystems on the earth and sustains life forms including mankind.
Components of ecosystem:
An ecosystem consists of three basic components, namely

(A) Abiotic components
(B) Biotic components and
(C) Energy component
A) Abiotic Components: Abiotic components include the non-living, inorganic, physical and chemical factors in the environment, e.g. Land, Air,Water, Calcium, Iron etc.
B) Biotic Components: Biotic components include plants, animals and micro organisms. Biotic components can be classified into three categories:
- Producers are self nourishing components of the ecosystem. Hence they are called Autotrophs. They are found both on land and water, e.g. Plants, Algae, Bacteria etc.
- Consumers are those that depend on producers, directly or indirectly. Hence they are called Heterotrophs.
C) Energy Components: All organisms in the biosphere use energy to work and convert one form of energy into another. The Sun is the ultimate source of energy for the biosphere as a whole. The solar energy gets transformed into other forms of energy through the various components in the ecosystem. The producers, consumers and the decomposers contribute a lot to the energy flow in an ecosystem.

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

Answer:
Functions of an ecosystem: The living organisms form an interacting set of flora and fauna which are organized into trophic levels, food chains and food webs. The functioning of an ecosystem depends on the pattern of the energy flow, as it helps in the distribution and circulation of the organic and inorganic matter within an ecosystem. Energy flow generally takes place in a hierarchical order in an ecosystem through various levels. These levels are called trophic levels. The chain of transformation of energy from one group of organisms to another, through various trophic levels is called a food chain. A system of interlocking and interdependent food chains is called a food web.

Question 3.
Explain about the aquatic biomes on Earth.
Answer:
Aquatic biome is a group of living organisms that live and interact with one another and its aquatic environment for nutrients and shelter. Like terrestrial biomes, aquatic biomes are influenced by a series of abiotic factors. It is broadly classified as fresh water biomes and marine biomes.
A. Fresh water Biomes: It comprises lakes, ponds, rivers, streams, wetlands etc. It is influenced by various abiotic components such as the volume of water, water flow, composition of oxygen, temperature, etc. Humans rely on freshwater biomes for drinking water, crop irrigation, sanitation and industry. Water lily, lotus, duck weeds etc. are the common plants found here. Trout, salmon, turtles, crocodiles etc. are the animals found here.
B. Marine Biomes: They are the largest aquatic biomes on earth. They are continuous bodies of salt water and provide a wide range of habitats for marine plants and animals. Coral reefs are a second kind of marine biomes within the ocean. Estuaries, coastal areas where salt water and fresh water mix, form a third unique marine biome. As water provides maximum mobility to marine organisms, nutrients are circulated more quickly and efficiently here than the terrestrial biomes. Apart from animals, plants such as kelp, algae, phytoplankton etc. also grow in water. Aquatic biomes are not only important for plants and animals, but also for humans. Humans use aquatic biomes for water, food and leisure activities. Some of the threats and issues to aquatic biomes are overfishing, pollution and rise in sea level.
VII. Find out the dates for the following:
1. World Wild Life Day - ............
2. International Day of Forest -
3. World Water Day - ...........
4. Earth Day - .............
5. World Environment Day - June 5th
6. World Oceans Day - ............

Answers:
1. March 3rd
2. March 21st
3. March 22nd
4. April 22nd
6. June 8th
VIII. Map Study

Locate the following on the world outline map.
1. Priairies
2. Downs
3. Tundra Biomes
4. Equatorial Biomes

You can identify and locate the above mentioned grasslands with the help of an atlas. Hint: Temperate grasslands are called differently in different parts of the world.
Prairies - North America
Downs - Australia and New Zealand
Tundra - Greenland, Arctic and Antarctic regions and Northern parts of Asia, Canada and Europe
Equatorial Biomes - Near the equator in Central and South America, parts of Africa and Asia
IX. Picture Study

Narrate the given food web of Arctic Tundra in your own words.
1. The flow of energy from the sun through an eco system can be illustrated in a food chain.
2. Within a food Chain there are produces. e.g., grasses, lichens, Arctic wild flower, etc.
3. Life in any biome includes producers (plants) and consumers (energy obtained from producers)
4. These consumers may be further classified as herbivores (plant eater) carnivores(meat eaters) (or) anniores (feed on combination of both animals and plants).

Additional Questions
I. Fill in the blanks.
1. ......... are self nourishing components of the ecosystem.
2. All living things, large or small are grouped into ....
3. The is the ultimate source of energy for the biosphere as a whole.
4. Decomposers live on dead and decaying plants and animals and are called ..........
5. The extinction of species (flora and fauna) due to human and natural influences is called ______
6. The branch of science that deals with ecosystem is called ..........
7. The temperate grasslands are called ...... in North America.
8. ........... is a fertile fresh water source found in deserts and semi-arid regions.

Answers:
1. Producers
2. species
3. sun
4. Saprotrophs
5. Lass of biodiversity
6. Ecology
7. Prairies
8. An Oasis
II. Choose the correct answer.

Question 1.

_______ the fourth sphere of the Earth.
(a) Lithosphere
(b) Hydrosphere
(c) Biosphere
(d) Atmosphere

Answer:
(c) Biosphere

Question 2.

_______ are found both on land and water.
(a) Autotrophs
(b) Heterotrophs
(c) Saprotrophs
(d) None of the above

Answer:
(a) Autotrophs

Question 3.
Consumers are those that depend on directly (or) indirectly are called _____
(a) Saprotrophs
(b) Heterotrophs
(c) Autotrophs
(d) None of the above

Answer:
(b) Heterotrophs

Question 4.
A group of living organisms that live and interact with One another on land is ________
(a) Tropical Savanna Biomes
(b) Tropical Forest Biomes
(c) Desert Biomes
(d) Terrestrial Biomes

Answer:
(d) Terrestrial Biomes

Question 5.
The chain of transformation of energy from one group of organisms to another through various trophic levels is called as
(a) Food chain
(b) Food web
(c) Trophic level
(d) None of the above

Answer:
(a) Food chain

Questions 6-8 are Assertion (A) Reason (R) type.
(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.

Question 6.
Assertion (A): In Biodiversity each species, no matter how big of small has an important role to play in the ecosystem.
Reason (R): It maintains the ecological balance.
Answer:
(A) Both Assertion (A) and Reason (R) are true. (R) explains (A).

Question 7.
Assertion (A): As the soil is sandy and saline deserts remain agriculturally unproductive. Reason (R): Tribal people who live in deserts practice food gathering and hunting. Answer:
(B) Both Assertion (A) and Reason (R) are true. (R) does not explain (A).

Question 8.
Assertion (A): Aquatic animals use $10 \%$ energy to obtain oxygen.
Reason (R): Terrestrial animals use only $2-4 \%$ of energy to obtain oxygen.
Answer:
(D) Both (A) and (R) are false.
III. Answer the following in brief.

Question 1.
What does an ecosystem consists of?
Answer:
An ecosystem consists of three basic components, namely
(A) Abiotic components
(B) Biotic components and
(C) Energy component.

Question 2.
Define Abiotic Components.
Answer:
Abiotic components include the non-living, in-organic, physical and chemical factors in the environment, e.g., Land, Air, Water, Calcium, Iron, etc.

Question 3.
What are energy components?
Answer:
All organisms in the biosphere use energy to work and convert one form of energy into another. The Sun is the ultimate source of energy for the biosphere as a whole. The solar energy gets transformed into other forms of energy through the various components in the ecosystem. The producers, consumers and the decomposers contribute a lot to the energy flow in an ecosystem.

Question 4.
State the unique weather condition that favours thick vegetative cover in the Tropical Forest Biomes.
Answer:
The climate in these biomes shows little seasonal variation with high annual rainfall and relatively constant, high temperature. This unique weather condition favours thick vegetative cover.

Question 5.
How do the people live Desert Biomes?
Answer:
People who live here practice food gathering and hunting. They move their temporary settlements frequently in search of pastures. Transportation becomes very difficult here and is carried on by camels. Reptiles like snakes, lizards, scorpions etc., are most commonly found here.

Question 6.
Mention the Temperate Grasslands in different parts of the world.
Answer:

Temperate grasslands are called differently in different parts of the world.
Prairies - North America

Steppes - Eurasia
Pampas - Argentina and Uruguay
Veld - South Africa
Downs - Australia and Newzealand.
Question 7.
What is an oasis?
Answer:
An oasis is a fertile fresh water source found in deserts and semi-arid regions. Oases are fed by springs. Crops like date palms, figs, citrus fruits, maize etc. are cultivated near these oases.

Question 8.
What is a Biosphere Reserve?
Answer:
A Biosphere Reserve is a special ecosystem or specialized environment with flora and fauna that require protection and nurturing. There are 18 Bioshpere Reserves in India.
IV. Distinguish the following.

Question 1.
Producers Consumers
Answer:

Question 2.
Abiotic components Biotic components

Answer:

Question 3.
Mention any 3 points between Aquatic ecosystem and Terrestrial ecosystem.

Answer:

V. Give reasons for the following.

Question 1.
Stable biosphere has to be conserved.
Answer:
A healthy eco system provides clean water, pure water, enriched soil, food, raw materials, medicines etc. Hence stable biosphere has to be conserved.

Question 2.
The Primary cause of today's loss of biodiversity.
Answer:
The primary cause of today's loss of biodiversity is habitat alteration caused by human activities. The ever increasing population results in over exploitation of biological resources. This has an adverse impact, on flora and fauna on earth. There are places on earth that are both biologically rich and deeply threatened.

Question 3.
The Net Primary productivity is low in Tundra.
Answer:
This biome experiences long severe winter and short cool summer. Due to the prevailing of low temperature and short growing seasons, the net primary productivity is very low in tundra.
VI. Answer in a paragraph.

Question 1.
Write down the differences between the Aquatic Ecosystem and Terrestrial Ecosystem.

Answer:

Question 2.
Desert Biomes.
Answer:
Deserts are usually found on the western margins of the continents between $20^{\circ}$ and $30^{\circ} \mathrm{N}$ and $\mathrm{S}$ latitudes. The annual rainfall is less than $25 \mathrm{~cm}$ in these regions. Due to the lack of rainfall and arid conditions, these regions do not possess any vegetation but have special vegetation type called Xerophytes. As the soil is sandy and saline, deserts remain agriculturally unproductive. Drought resistant thorny scrubs and bushes, palms are found here.

Tribal people who live here practice food gathering and hunting. They move their temporary settlements frequently in search of pastures. Transportation becomes very difficult here and is carried on by camels. Reptiles like snakes, lizards, scorpions etc., are most commonly found here.