7th Forest products and Waste management [Science class VII]

Holy faith abc of Science

I. Long answer type question

1. What are different ways of solid waste disposal?      

Ans : Following are different ways of solid waste disposal

(a)Solid waste is burnt and ash is removed from time to time

(b)Solid waste is buried in low lying area to level uneven ground

(c) Domestic solid waste are buried in a pit to make compost

(d)Non biodegradable solid wastes are recycled and reused

2. Why are forests such a valuable resources?

Ans: Forest product play vital role in socio-economic development. We get food (cereals, pulses, fruits), firewood, fibre, construction material, industrial products (tannins, lubricants, dyes, resins, perfumes) and products of medicinal importance.  It is also the home of diverse wildlife which maintains the ecosystem. Thus forests are valuable resources.

 3. List the various ways in which we can conserve forest?           

Ans: The various ways in which we can conserve forest are:

(i)Deforestation should be compensated by Afforestation.

(ii) Discourage the uses of firewood

(iii)By controlling forest fire applying anti-fire solution

(iv)Controlling overgrazing

(v) Educating people about the importance of forest.

4. List some uses of forest?

Ans: some uses of forest are:

(i) Forest purifies air and prevent air pollution

(ii)Forests recycle water into atmosphere

(iii) Forest bind soil and prevent soil erosion.

(iv) Forest gives us food, timber and medicinal materials

5. What are the techniques of waste management?

Ans: Following are the techniques of waste management

(i) Reduce consumption or find its substitute

(ii)Try to reuse it again and again in other form

(iii) Recover material for recycling

(iv)  Produce energy from the waste,

 II. Short answer type questions

1. How can an individual contribute in improving the quality of life?

Ans: An individual can contribute in improving the quality of life by :

(i)By thinking globally and act personally.

(ii) Joining hand with other to sustain and heal the earth.

(iii) By learning the how nature we are dependent on each other.

(iii) By giving protection and respect to every organism

2. List some problem caused by deforestation?

Ans: (i) Ecosystem and the ecological balance get disturbed.(ii)There is increase in global warming

(iii)Soil erosion will increases

(iv) Wild life may  not survive for long time.  

3 . What is waste management?

Ans: Waste management is the process of collection, transportation and disposal of waste materials.                                                                                                                                   

4. How is sea wage treated?  

Ans:   Treatment of sewage includes removal of solid waste from sewage and making liquid part less harmful.  In sewage treatment plant at first large solid material are removed by passing through vertical bars.  Now Liquid waste left is made to pass settling tank small sized solid impurities live sand or gravel are removed. After this, water is sent to sedimentation tank to separate organic waste. At last left water is chlorinated before releasing into water bodies.
5. How plants and animal interdependent?

Ans: Plants produce food using co₂ given by animals where as oxygen given by plant is used by animals. Animal help plant in pollination and dispersal of seeds and plant provide valuable food and medicinal product. Plants give shelter for animals where as animals excreta provide mineral for growth. Thus we can say that plants and animal interdependent.

III. Very short answer type questions

1. What is food chain?

Ans: A Food chain is a series of organisms depending on next one to feed upon.

2. What do you mean by planed harvesting of forest?

Ans: Use of modern management system that ensures that forest values will be protected during harvesting is called planed harvesting.

3.”You conserve forest, you conserve soil” Justify this statements.

Ans: Forests bind soil with roots and prevent soil erosion. They maintain fertility of soil and check flood.

4. Which should be bigger: those used for sea wage disposal or those used for storm water disposal?

Ans: storm water disposal            

5. Write short notes on: (a)Industrial effluent  (b) Sewage treatments (c) Forest conservation (d)Rainwater harvesting

Ans:

(a)Industrial effluent: The water discharged by the industries into drains and river that causes water pollution is called Industrial effluent.

(b) Sewage treatments: Treatment of sewage includes removal of solid waste from sewage and making liquid part less harmful is called Sewage treatments .  

 (c) Forest conservation: Management, protection and wise use of forest resources is called Forest conservation.

(d) Rainwater harvesting: The practice of storing rain water for further use is called rainwater harvesting. 
6. Distinguish between- (a) flora and fauna (b) tropical evergreen forest and deciduous forest.

(c) Thorn forest and mangrove forest.

Ans: (a) Flora and fauna is the term given to the plant life and animal life respectively. Their interactions comprise the ecosystem and the biodiversity on the planet earth. Hence, they are obviously inter-related.

(b)An temperate evergreen forest is a forest consisting entirely or mainly of evergreen trees that retain green foliage all year round. Deciduous trees lose their leaves in fall. The natural decaying of the fallen leaves enriches the soil and supports all kinds of plant and animal life.

 (c)The thorn forests are found in the region getting rainfall less than 70 cm . Mangrove Forests are found in the delta regions. The trees in the mangrove forests have roots completely submerged in water. They are dense and provide hard and durable timber

7. What are crown and Canopy?       

Ans: The part of the tree with branches is known as the crown. When the crown of tall trees in the forests forms a roof-like covering over the other plants, it is known as a canopy.

8. What is desertification?

Ans: The process by which fertile land becomes desert, due to drought, deforestation, or inappropriate agriculture is called desertification.

IV. Fill in the blanks

(a)The loss of ------- is the greatest threat of wildlife. [Forest]

(b)Sea water is unfit for ------------- purpose. [domestic]

(c) Waste is a material having no ------------ utility. [further]

(d)The sewage systems were ------- type in olden days.[three]

(e)Discharge of waste water from industries is known as ------------- [Industrial effluent]