81) Which trees out of coconut, cactus, acacia and cinchona are found in mangrove forests?
Answer: Only the coconut tree is found in mangrove forests. Cactus and acacia are found in thorn forests, while cinchona trees are found in tropical evergreen forests.
82) Which wetland of India is very popular with flamingoes which are nesting?
Answer:The Rann of Kuchchh is the wetland most popular with flamingoes which are nesting.
83) What kinds of commercially important trees are found in tropical evergreen forests?
Answer: Some of the commercially important trees found in tropical evergreen forests are ebony, mahogany, rosewood, rubber and cinchona.
84) What is a bio-reserve? Give two examples.
Answer:Bio-reserves are sites established by countries and recognised under UNESCO's Man and the Biosphere (MAB) Programme to promote sustainable development based on local community efforts and sound scientific principles. Examples of bio-reserves are the Nilgiris and Nanda Devi.
85) Define an ecosystem.
Answer:An ecosystem is a life-supporting system comprising the physical environment i.e., non-living components like climate, soil, rivers, etc along with all organisms living therein.
86) Name two animals having habitat in tropical and montane type of vegetation.
Answer: Animals having habitat in tropical type of vegetation are elephants, monkeys, rats, etc. Animals having habitat in montane type of vegetation are spotted deer, Kashmir stag, antelope, etc.
87) In which region are the tropical thorn forests and scrubs found in India? Mention any four characteristics of such type of vegetation.
Answer:Such forests are found in semi-arid areas of Gujarat, Rajasthan, Madhya Pradesh, Andhra Pradesh, Karnataka, Uttar Pradesh and Haryana.
Their characteristics are
(i) Trees are scattered and have long roots penetrating deep into the soil in order to get moisture.
(ii) The stems are succulent to conserve water.
(iii) Leaves are mostly thick and small to minimize evaporation.
(iv) Acacias, palms, euphorbias and cacti are the main plant species found in these forests.
88) Explain why forests are important for human beings.
Answer:Forests are important for human beings because they are renewable resources that enhance the quality of the environment. They help in modifying local climate, control soil erosion, regulate stream flow, support wood based industries, support the livelihood of many communities and also offer a scenic view for recreation. They also reduce the force of wind and thus reduce effects of storms, maintain temperature and cause rainfall. They also provide humus to the soil and shelter to wildlife, thus preserving biodiversity
89) Explain any three measures taken by the government to protect the flora and fauna of the country.
Answer:To protect the flora and fauna of the country, the government has taken the steps which include
(i) 89 National Parks, 49 Wildlife Sanctuaries and many Zoological Gardens have been set up to take care of our natural heritage.
(ii) 18 Biosphere Reserves have been set up in the country to protect flora and fauna.
(iii) Project Tiger, Project Rhino, Project Great Indian Bustard and many other eco-developmental projects have been introduced by the government to protect endangered species of wildlife.
90) How do human beings influence the ecology of a region? Explain.
Answer:Due to the excessive exploitation of the plant and animal resources by human beings, the ecosystem has been disturbed. The greed of human beings leads to over-utilisation of natural resources. They cut the trees and kill animals, creating ecological imbalance. As a result, some of the plants and animals have reached the verge of extinction.
91) What are the differences between moist deciduous and dry deciduous forests?
Answer: Differences between moist deciduous and dry deciduous forests
Moist Deciduous Forests
Dry Deciduous Forests
Found in areas with annual rainfall between 100 and 200 cm.
Found in areas with annual rainfall between 70 and 100cm.
Teak, bamboo, sal, shisham sandalwood, khair, kusum, arjun and mulberry trees are found.
Teak, sal, neem and peepal trees are found.
Not many have been cleared.
Large areas have been cleared for cultivation and grazing.
Cover about 34% of India's forested area.
Cover about 30% of India's forested area.
92) How are thorn forests different from mangrove forests?
Answer: Thorn forests and mangrove forests are different in following ways
Found in areas with annual rainfall less than 70 cm.
Found in the delta regions of rivers and are not dependent on amount of rainfall.
Babool, kikar, palm, cactus and acacia trees / bushes are found.
Sundari, palm, coconut keora and agar trees are found
Found in most of Rajasthan, Northern part of Gujarat and in some areas of Uttar Pradesh, Haryana and Deccan Plateau.
Found in the coastal delta regions (delta areas of rivers on the East coast of India).
93) Natural vegetation refers to a plant community which has grown naturally without human aid and has been left undisturbed by humans for a long time. This is termed as a virgin vegetation. Thus, cultivated crops and fruits, orchards form part of vegetation but not natural vegetation. Read the above passage and answer the following questions (a) What do you mean by virgin vegetation? (b) How agricultural crops are different from virgin vegetation? (c) What values you have learnt from the given passage?
Answer: (a) Virgin vegetation is a vegetation that grows naturally without any human effort. It is left undisturbed by human beings for a long time. (b) Agricultural crops are grown by human beings, so they are entirely different from virgin vegetation. (c) From this passage, I have learnt that the natural vegetation is our living heritage. We should preserve it.
94) Identify some medicinal plants in your area. Which plants are used as medicines by local people to cure diseases?
Answer:Some medicinal plants found in our area with diseases they can cure are given below
(i) Bel Fruit The ripe fruit cures gastro intestinal problems.
(ii) Iswarmula Root Its decoction cures constipation.
(iii) Satawari Tuber It cures gastro intestinal problems.
(iv) Dimiri Leaf and Stem Fresh juice (50-100 mL) of leaves is given with water for about 10 days to treat gastro intestinal problems.
95) Why are forests very important to human beings and the environment around them? Explain.
Answer:For the following reasons, forests are very important to human beings and the environment around them
(i) Forests modify local climate, control soil erosion and regulate stream flow.
(ii) Forests support a variety of industries, provide livelihood for many communities and offer panoramic or scenic view for recreation,
(iii) Forests control wind force and temperature and cause rainfall.
(iv) They provide humus to the soil and shelter to the wildlife.
(v) Forests help us to keep our environment clean and pollution free by preventing dust from entering into the air, absorbing carbon dioxide and releasing fresh oxygen.
(vi) Forests stop rainwater from flowing fast and hold it so that it could percolate down to enrich the ground water level (water table).
96) What is meant by vegetation? How much natural is the natural vegetation of India today?
Answer:Natural vegetation refers to a plant community which has grown naturally without human aid and has been left undisturbed by humans for a long time. Today natural vegetation has not been left natural anymore because of the following reasons
(i) Various new species of plants are raised in laboratories and they are planted to have better results.
(ii) Human interference is continuously increasing day by day which is deteriorating the quality of nature and is harmful for humans too.
97) Distinguish between flora and fauna.
Answer:Differences between flora and fauna are (i) The term flora is used to denote plants of a particular region or period. The species of animals are referred to as fauna.
(ii) Flora remains at one place but fauna moves from one place to another.
(iii) About 47,000 plant species and 89,000 species of animals are found in India.
98) "In mountainous area, there is change in natural vegetation due to decrease in temperature". Justify giving examples from different zones.
Answer:The following examples justify the given statement
(i) Between the heights of 1,000 and 2,000 metres, wet temperate type of forests are found. Evergreen broad-leafy trees such as oaks and chestnuts predominate.
(ii) Between 1,500 and 3,000 metres, temperate forests containing coniferous trees like pine, deodar, silver fir, spruce and cedar are found.
(iii) At high altitudes, generally more than 3,600 metres above the sea-level, temperate forests and grasslands give way to the alpine vegetation. Silver fir, junipers, pines and birches are the common trees of these forests.
(iv) At higher altitudes, mosses and lichens form part of Tundra vegetation.
99) Explain any three characteristics of Tropical evergreen forest.
Answer: Three characteristics of tropical evergreen forests are
(i) The trees reach great height upto 60 metres or even above. Trees are tall, thick and have vigorous growth.
(ii) As the region is warm and wet throughout the year, it has a luxuriant vegetation of all kinds-trees, shrubs and creepers giving it a multilayered structure.
(iii) There is no definite time for trees to shed their leaves, as such forests appear green all the year round.
100) What are bio-reserves? Why are they created? Or What is biosphere reserve? Mention any two uses of biosphere reserve.
Answer: In the bio-reserves, plant and animal species are protected so that this natural heritage can be transmitted to future generations.
(i) In each biosphere reserve the core will preserve wildlife, the flora and the fauna in their natural forms.
(ii) The surrounding zone would be utilised for research and experimentation in developing forests and other products.
101) In which part of India, Mangrove forests are found? Mention two characteristics of these forests. Or Explain any three features of Mangrove forests.
Answer:Mangrove forests are found in Ganga-Brahmaputra delta, Krishna, Kaveri, Godavari and Mahanadi delta. Characteristics of these forests are as follows
(i) Roots of these plants remain submerged under water.
(ii) Sundari is the most important tree in these forests.
(iii) Royal Bengal Tiger is famous animal in these forests.
102) A great variety of flora is found in India. Give three geographical factors responsible for this diversification of flora.
Answer:About 47,000 plant species and 89,000 species of animals are found in India. Following are the factors responsible for a great variety of flora found in India
(i) Varied relief features
(ii) Varied landforms
(iii) Terrains and soils
(iv) Range of daily and annual temperature.
103) In which region are the thorny forests and scrubs found in India? Mention any two characteristics of such type of vegetation. Or Explain any three features of the thorn forests and scrubs.
Answer: Thorny forests and scrubs are found in the North-Western part of the country including semi-arid areas of Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh and Haryana. Characteristics of the thorn forests and scrubs are as follows (i) Trees are scattered and have long roots penetrating deep into the soil in order to get moisture. (ii) The stems are succulent to conserve water. (iii) Leaves are mostly thick and small to minimize evaporation.
104) (a) What will happen if plants and animals disappear from the Earth's surface? (b) Can human beings survive under such a situation? (c) Why is biodiversity necessary and why should it be conserved?
Answer: (a) If the plants and animals disappear from the Earth's surface, then the ecological balance will be disturbed. Without plants there will be no oxygen available for breathing after some time and everybody will die.
(b) Biodiversity means biological diversity i.e., there are many animal and plant species on our planet spread all over the world. These animal and plant species, including humans, are all interdependent.
(c) Each species has its own place and role to play in the environment and help in the maintaining the ecological balance. That's why it should be conserved.
105) Distinguish between tropical evergreen and deciduous forests.
Answer: Differences between tropical evergreen and deciduous forests are
Tropical Evergreen Forests
Tropical Deciduous Forests
They grow in areas of heavy rainfall 200 cm and above.
They grow in areas receiving rainfall between 200 cm and 70cm.
There is no definite time for trees to shed their leaves.
The trees shed their leaves for about 6 to 8 weeks in the dry summer.
Ebony, mahogany, rosewood, rubber and cinchona are the important
Teak, Bamboo, Sal, Shisham, Sandalwood, Khair Kusum, Arjun, Peepal and Neem are the important trees of these,
Common animals found in these forests are elephants, monkeys, lemur, deer and the one horned rhinoceros.
Common animals found in these forests are lion, tiger, deer and elephant.
Plenty of birds, bats sloth, scorpions and snails are also found in these jungles.
A huge variety of birds, lizards, snakes and tortoises are found in these forests.
These forests are found in areas of the Western Ghats and the island group of Lakshadweep, Andaman and Nicobar, upper parts of Assam and the Tamil Nadu coast
These forests are found mostly in the Eastern part of India, North-Eastern states along the foothills, the Himalayas, Jharkhand, Odisha, Chhattisgarh, on the Western slopes of Western Ghats, Madhya Pradesh, Bihar and Uttar Pradesh.
106) "Every species has a role to play in the ecosystem". Elaborate the statement.
Answer:An ecosystem comprises the physical environment. It is an interlinked system with the plants and animals living therein linked to each other. Ecosystems have evolved over a period of thousands of years. Some examples of interlinking are
(i) Insects help in pollination of crops and fruit trees. Some insects also exert biological control on harmful insects.
(ii) Carnivorous animals kill herbivorous animals for food and herbivorous animals consume plants for food.
(iii) Decomposers like fungi and bacteria fertilise the soil with humus by decomposing dead animals and plants to enable plants to grow. There are many such examples of interlinking to show that every species has a role to play in the ecosystem.
107) Which values do the national parks of our country promote?
Answer:Our national parks promote the values given below
(i) They promote the rebuilding of our forest wealth, as the forest cover in India is just over 20%, whereas it should be about 33% for balancing the ecosystem.
(ii) They promote safety of animals, which is required for many species which are endangered. If these species become extinct, the ecosystem will be unbalanced, leading to more problems in future.
(iii) They promote the utilisation of herbs and plants as an occupation for the tribal and local communities living in or around the areas where the national parks are located. The methods of making these traditional medicines should not be lost to the world, as such medicines are free from the side effects which are caused by antibiotics.
(iv) Reviving the ecology system is an important value which will make the world a better place to live in for future generations.
108) Why should we conserve both flora and fauna? Explain with some examples.
Answer: We can understand why flora and fauna should be conserved by understanding their use with the examples given below
(i) Among flora, trees provide us their wood to serve our various requirements, besides providing shelter from the hot sun in summer.
(ii) Crops provide our food including cereals, vegetables and fruits.
(iii) Many plant extracts are used for making medicines to cure and prevent diseases.
(iv) Among fauna, milch animals provide milk products as food.
(v) Poultry animals provide eggs and other animals as well as fish are also providing us food articles.
(vi) Insects help in pollination of crops and biologically control other harmful insects. All these maintain a balanced ecosystem and so should be conserved.
109) What is the importance of biosphere reserves?
Answer: Bio-reserves achieve three interconnected functions, i.e., conservation, development and logistic support. To fulfil these functions, they contain three interconnected zones.
(i) Core zone It is a securely protected site for conserving biological diversity, monitoring minimally disturbed ecosystems and undertaking non-destructive research and other low-impact uses like education.
(ii) Buffer zone It surrounds or adjoins the core area and is used for cooperative activities compatible with sound ecological practices, including environmental education, recreation, ecotourism and applied and basic research.
(iii) Transition/development zone It may contain a diversity of agricultural activities, settlements and other uses and in which local communities, management agencies, scientists, NGOs, cultural groups, economic interests and other stakeholders work together to manage and sustainably develop the area's resources. Thus, properly managed biosphere reserves are important for preserving biological diversity.
110) Name different types of vegetation found in India and describe the vegetation of high altitudes.
Answer:The different types of vegetation found in India are
(i) Tropical Evergreen or Rainforests
(ii) Tropical Deciduous Forests
(iii) Tropical Thorn Forests and Scrubs
(iv) Montane Forests
(v) Mangrove Forests (Tidal Forests) The type of vegetation found at the high altitudes is Montane forest type. Its features are found at high altitudes in mountainous areas.
(a) There is a succession of natural vegetation belts
(b) They vary with altitude as follows
(i) 1000m-2000m Wet temperate forests. Evergreen broad leaf trees like oaks and chestnuts predominate here.
(ii) 1500m-3000m Temperate forests containing coniferous trees like Pine, Deodar, Silver Fir, Spruce and Cedar. These cover mostly the Southern slopes of the Himalayas.
(iii) 3000m-3600m These are temperate grasslands.
(iv) Above 3600m Here we find Alpine vegetation. Silver fir, junipers, pines and birches are common. At even higher altitudes and with the approach of the snowline, the vegetation changes from shrubs and scrubs to alpine and grasslands. Only mosses, lichens and very small shrubs grow during the very short summer, which is called Tundra type of vegetation.