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?
(a) Biodiversity may be defined as the variety of different life forms like plants, animals and microorganisms in an area. Both plants and animals are dependent on each other for the survival. They help each other by the exchange of gases. It means if we remove the one, then it will affect the survival of other organisms or species. To maintain a balance in nature we conserve biodiversity.
(b) Protected forests are also not completely safe for wild animals because as we know forests are the source of food and shelter. So, the people who live near the forests or who lives in the forests uses resources of forests to fulfil their own requirements. People get food, wood and many other things from the forests. People cut wood and kill animals and sell them for money.
(c) Some tribals depend on the jungle as they get food, shelter, fodder and fallen leaves from the jungle. These are their daily needs. So, the tribals depend on forests for their daily needs and for their survival too.
(d) Deforestation is the removal of trees.
Causes of deforestation are as follows:
Consequences of deforestation are as follows:
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
Find out the information about the national parks in your state. Identify and show their location on the outline map of India.
Differentiate between the following:
(a) Wildlife sanctuary and biosphere reserve
(b) Zoo and wildlife sanctuary
(c) Endangered and extinct species
(d) Flora and fauna
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.
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.
How can you contribute to the maintenance of green wealth of your locality? Make a list of actions to be taken by you.
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.
Explain how deforestation leads to reduced rainfall.
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.
Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the Earth?
Prepare a brief speech on global warming that you have to make in your class.
Describe the construction of a kaleidoscope.
Explain the importance of reproduction in organisms.
What is menstruation? Explain.
Name the microorganisms which can fix atmospheric nitrogen in the soil.
A pendulum oscillates 40 times in 4 seconds. Find its time period and frequency.
Make sketches of animal and plant cells. State three differences between them.
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
Make a sketch of the human nerve cell. What function do nerve cells perform?