Basic Science Solutions for Class 7 Science Chapter 17 Forests are provided here with simple step-by-step explanations. These solutions for Forests are extremely popular among Class 7 students for Science Forests Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Basic Science Book of Class 7 Science Chapter 17 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Basic Science Solutions. All Basic Science Solutions for class Class 7 Science are prepared by experts and are 100% accurate.

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 Five forest products are:

• Bamboo
• Timber
• Rubber, gum and resin
• Medicines
• Food

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Forests maintain a balance in the levels of oxygen and carbon dioxide in the atmosphere. They also absorb huge amounts of dust particles and other pollutants.

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Forests regulate the temperature of the atmosphere. The trees release water vapour during transpiration and cool the atmosphere. They also maintain a balanced level of carbon dioxide in the atmosphere.

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The term 'extinct' refers to something that is no longer in existence or that has ended or died out completely on earth.

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During photosynthesis, trees utilise carbon dioxide and release oxygen. On the other hand, during respiration, they utilise oxygen and release carbon. Thus, photosynthesis and respiration help forests maintain the levels of these gases in the atmosphere.

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Tribal and other people living near forests rely heavily on forests for their livelihoods. They collect fruits, leaves and tubers and also hunt animals for food. They use grass and bamboo for constructing houses.

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When deforestation occurs, soil is lost because there are no trees to save it from the direct impact of rain or flowing water. This leads to the loss of resistance provided to the fast-flowing river water, which ultimately causes floods. In deforested mountains, when heavy rains occur, water comes down with a great force because there are no trees to resist the flow.

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During rains and snowfalls, forests trap the water and recharge the groundwater. Forests also act as check dams and slow down the water flow, which again helps in recharging the groundwater. Without forests, this water runs straight to streams or rivers, eroding large amount of soil on its path and causing floods. Trees release water in the form of vapours through small pores in their leaves called stomata. This helps in bringing the rain.

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Forests have grasses and trees that have extensive root system. These roots bind soil particles and prevent them from the actions of air and water. During rains, leaves of big trees create obstructions on the path of rain drops. These leaves prevent direct exposure of soil particles with raindrops.

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All the organisms in a forest are interdependent. Every organism, plant or animal uses other organisms or their products for survival.
Plants produce their food by using sunlight through the process of photosynthesis. Other organisms depend on plants to fulfil their energy needs. Herbivores depend only on plants for food and thus, they consume plants. Carnivores, in turn, consume herbivores, thereby forming a food chain.
Big trees provide shelter to birds and many small animals. They provide protection and space to birds to build their nests and groom their young ones.

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Impacts of deforestation on animals living in forests:
(a) It leads to the loss of hiding place for small animals and birds. This allows them to get exposed to larger carnivores, who in turn hunt them easily.
(b) It also leads to the loss of nesting place for birds and small rodents.  
(c) Herbivores that are completely dependent on plants for food flee from deforested region, which no longer have enough food for them. Loss of herbivores in a region ultimately leads to the decline in the population of carnivores. 
(d) A deforested region becomes prone to flash floods and wind erosion. Further, it gets degraded and becomes unsuitable for habitation of animals.

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Answer:

A B
Cane Furniture
Eucalyptus Oil
Coniferous trees Paper
Rubber tree Tyres
Babool Gum



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