Class 7 Science - Chapter Winds, Storms and Cyclones NCERT Solutions | Which of the statements given below is c

Explain why holes are made in hanging banners and hoardings.

Which one of the following place is unlikely to be affected by a cyclone.

(i) Chennai          (ii) Mangaluru (Mangalore)                                                                                                                                                                                              (iii) Amritsar        (iv) Puri

What planning is required in advance to deal with the situation created by a cyclone?

Suggest two methods to find out wind direction at a given place.

Fill the missing word in the blank spaces in the following statements:

(a) Wind is——————air.
(b) Winds are generated due to —————— heating on the earth.
(c) Near the earth’s surface __________air rises up whereas ___________ air comes down.
(d) Air moves from a region of ——— pressure to a region of ———.

How will you help your neighbours in case cyclone approaches your village/town?

State two experiences that made you think that air exerts pressure (other than those given in the text).

You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.

State similarities and differences between the laboratory thermometer and the clinical thermometer.

State differences between acids and bases.

Classify the changes involved in the following processes as physical or chemical changes:
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f ) Digestion of food

Name the elements that determine the weather of a place.

In addition to the rock particles, the soil contains

(i) air and water
(ii) water and plants
(iii) minerals, organic matter, air and water
(iv) water, air and plants

Why does an athlete breathe faster and deeper than usual after finishing the race?

Match structures given in Column I with functions given in Column II.

Column I                           Column II
(i) Stomata                        (a) Absorption of water
(ii) Xylem                           (b) Transpiration
(iii) Root hairs                    (c) Transport of food
(iv) Phloem                        (d) Transport of water
                                          (e) Synthesis of carbohydrates

Fill in the blanks:

(a) Production of new individuals from the vegetative part of parent is called_____________.
(b) A flower may have either male or female reproductive parts. Such a flower is called_____________.
(c) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as _____________.
(d) The fusion of male and female gametes is termed as _____________.
(e) Seed dispersal takes place by means of _____________, _____________ and _____________.

Classify the following as motion along a straight line, circular or oscillatory motion:

(i) Motion of your hands while running.
(ii) Motion of a horse pulling a cart on a straight road.
(iii) Motion of a child in a merry-go-round.
(iv) Motion of a child on a see-saw.
(v) Motion of the hammer of an electric bell.
(vi) Motion of a train on a straight bridge.

Why do organisms need to take food?

What are decomposers? Name any two of them. What do they do in the forest?

Will the compass needle show deflection when the switch in the circuit shown by Fig.14.24 is closed?

Give a brief description of the process of synthesis of food in green plants.

Match structures given in Column I with functions given in Column II.

Column I                           Column II
(i) Stomata                        (a) Absorption of water
(ii) Xylem                           (b) Transpiration
(iii) Root hairs                    (c) Transport of food
(iv) Phloem                        (d) Transport of water
                                          (e) Synthesis of carbohydrates

Choose the correct option from the following:
Plants take carbon dioxide from the atmosphere mainly through their:
(i) roots (ii) stem (iii) flowers (iv) leaves

Fill in the blanks.
(i) The blood from the heart is transported to all parts of the body by the.
(ii) Haemoglobin is present in cells.
(iii) Arteries and veins are joined by a network of .
(iv) The rhythmic expansion and contraction of the heart is called.
(v) The main excretory product in human beings is.
(vi) Sweat contains water and.
(vii) Kidneys eliminate the waste materials in the liquid form called.
(viii) Water reaches great heights in the trees because of suction pull caused by .

What is sewage? Explain why it is harmful to discharge untreated sewage into rivers or seas.

Mark ‘T’ if the statement is true and ‘F’ if it is false:

(a) The freshwater stored in the ground is much more than that present in the rivers and lakes of the world. (T/F)
(b) Water shortage is a problem faced only by people living in rural areas. (T/F)
(c) Water from rivers is the only source for irrigation in the fields. (T/F)
(d) Rain is the ultimate source of water. (T/F)

Fill in the blanks:

(a) An image that cannot be obtained on a screen is called ____________.
(b) Image formed by a convex __________ is always virtual and smaller in size.
(c) An image formed by a __________ mirror is always of the same size as that of the object.
(d) An image which can be obtained on a screen is called a _________ image.
(e) An image formed by a concave ___________ cannot be obtained on a screen.

Name two chemicals used to disinfect water.