Class 8 Science - Chapter Conservation of Plants and Animals NCERT Solutions | Find out the information about the natio

Discuss the effects of deforestation on the following:
(a) Wild animals
(b) Environment
(c) Villages (Rural areas)
(d) Cities (Urban areas)
(e) Earth
(f) The next generation

Answer in brief:
(a) Why should we conserve biodiversity?
(b) Protected forests are also not completely safe for wild animals. Why?
(c) Some tribals depend on the jungle. How?
(d) What are the causes and consequences of deforestation?
(e) What is Red Data Book?
(f) What do you understand by the term migration?

Complete the word puzzle:
Down
1. Species on the verge of extinction.
2. A book carrying information about endangered species.
5. Consequence of deforestation.
Across
1. Species which have vanished.
3. Species found only in a particular habitat.
4. Variety of plants, animals and microorganisms found in an area.

Differentiate between the following:
(a) Wildlife sanctuary and biosphere reserve
(b) Zoo and wildlife sanctuary
(c) Endangered and extinct species
(d) Flora and fauna

Why should paper be saved? Prepare a list of ways by which you can save paper.

In order to meet the ever-increasing demand in factories and for shelter, trees are being continually cut. Is it justified to cut trees for such projects? Discuss and prepare a brief report.

Explain how deforestation leads to reduced rainfall.

What will happen if:
(a) we go on cutting trees.
(b) the habitat of an animal is disturbed.
(c) the top layer of soil is exposed.

How can you contribute to the maintenance of green wealth of your locality? Make a list of actions to be taken by you.

Fill in the blanks:
(a) A place where animals are protected in their natural habitat is called                  .
(b) Species found only in a particular area is known as                          .
(c) Migratory birds fly to far away places because of                     changes.

Which of the following can be beaten into thin sheets?
  (a) Zinc     (b) Phosphorus     (c) Sulphur     (d) Oxygen

Fill in the blanks
(a) Most liquids that conduct electricity are solutions of , ______________ and ______________.
(b) The passage of an electric current through a solution causes ______________ effects.
(c) If you pass current through copper sulphate solution, copper gets deposited on the plate connected to the terminal of the battery.
(d) The process of depositing a layer ofany desired metal on another material by means of electricity is called .

Give two examples each of situations in which you push or pull to change the state of motion of objects.

Fill in the blanks:
(a) Friction opposes the _____________ between the surfaces in contact with each other.
(b) Friction depends on the _____________ of surfaces.                                                                                                                                                                      (c) Friction produces __________.
(d) Sprinkling of powder on the carrom board ________ friction.
(e) Sliding friction is ___________ than the static friction.

List conditions under which combustion can take place.

Indicate whether the following statements are True (T) or False (F).
(a) Unicellular organisms have one-celled body. (T/F)
(b) Muscle cells are branched. (T/F)
(c) The basic living unit of an organism is an organ. (T/F)
(d) Amoeba has irregular shape. (T/F)

Which of the following cannot be charged easily by friction?
(a) A plastic scale
(b) A copper rod
(c) An inflated balloon
(d) A woollen cloth.

Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.

What are the different ways in which water gets contaminated ?

Explain the importance of reproduction in organisms.

Fill in the blanks:
(a) Burning of wood and coal causes                   of air.
(b) A liquid fuel, used in homes is                            .
(c) Fuel must be heated to its                                    before it starts burning.
(d) Fire produced by oil cannot be controlled by                        .

Name the unit in which the calorific value of a fuel is expressed.

Prepare a list of objects around you that are electroplated.

Write 10 lines on the usefulness of microorganisms in our lives.

Tick the correct answer:

(a) Yeast is used in the production of
      (i) sugar     (ii) alcohol     (iii) hydrochloric acid     (iv) oxygen

(b) The following is an antibiotic
      (i) Sodium bicarbonate     (ii) Streptomycin      (iii) Alcohol     (iv) Yeast

(c) Carrier of malaria-causing protozoan is
      (i) female Anopheles mosquito     (ii) cockroach     (iii) housefly     (iv) butterfly

(d) The most common carrier of communicable diseases is
      (i) ant     (ii) housefly     (iii) dragonfly     (iv) spider

(e) The bread or idli dough rises because of
      (i) heat     (ii) grinding     (iii) growth of yeast cells     (iv) kneading

(f) The process of conversion of sugar into alcohol is called
     (i) nitrogen fixation     (ii) moulding     (iii) fermentation     (iv) infection

Match items in column A with one or more items in column B:

A                                           B
(i) Inner planets                 (a) Saturn
(ii) Outer planets               (b) Pole Star
(iii) Constellation               (c) Great Bear
(iv) Satellite of the Earth   (d) Moon
                                          (e) Earth
                                          (f) Orion
                                          (g) Mars

Mention against each of the following whether regular or diffused reflection will take place when a beam of light strikes. Justify your answer in each case.
(a) Polished wooden table (b) Chalk powder
(c) Cardboard surface        (d) Marble floor with water spread over it
(e) Mirror                            (f) Piece of paper

What is a constellation? Name any two constellations.

What is metamorphosis? Give examples.

Describe the ‘Green House Effect’ in your own words.