Class 7 Science - Chapter Fibre to Fabric NCERT Solutions | Which of the following does not yield wo

Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down                                               Across
(D) 1 : Thorough washing           (A) 1 : Keeps warm
      2 : Animal fibre                            2 : Its leaves are eaten by silkworms
      3 : Long thread like structure      3 : Hatches from egg of moth

Match the words of Column I with those given in Column II:
Column I                         Column II
1. Scouring                      (a) Yields silk fibres
2. Mulberry leaves           (b) Wool yielding animal
3. Yak                              (c) Food of silk worm
4. Cocoon                        (d) Reeling
                                        (e) Cleaning sheared skin

Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.

What is meant by the following terms?
(i) Rearing     (ii) Shearing     (iii) Sericulture

The silkworm is: (a) a caterpillar, (b) a larva. Choose the correct option.
(i) a     (ii) b     (iii) both a and b     (iv) neither a nor b.

Out of the following, which are the two terms related to silk production? Sericulture, floriculture, moriculture, apiculture and silviculture.

Hints:
(i) Silk production involves cultivation of mulberry leaves and rearing silkworms.
(ii) Scientific name of mulberry is Morus alba.

Given below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.
Shearing, __________, sorting, __________, __________, _________.

You must be familiar with the following nursery rhymes:
(i) ‘Baa baa black sheep, have you any wool.’
(ii) ‘Mary had a little lamb, whose fleece was white as snow.’

Answer the following:
(a) Which parts of the black sheep have wool?
(b) What is meant by the white fleece of the lamb?

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.

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 ———.

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.

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

In the circuit shown in Fig. 14.25

(i) Would any of the bulb glow when the switch is in the ‘OFF’ position?
(ii) What will be the order in which the bulbs A, B and C will glow when the switch is moved to the ‘ON’ position?

Name the following:
(i) A parasitic plant with yellow, slender and tubular stem.
(ii) A plant that has both autotrophic and heterotrophic mode of nutrition.
(iii) The pores through which leaves exchange gases.

Which of the following distance-time graphs shows a truck moving with speed which is not constant?

When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.

State the characteristics of the image formed by a plane mirror.

Match the items in Column I with those in Column II:
Column I                                              Column II
(i) A home for living organisms         (a) Large particles
(ii) Upper layer of the soil                 (b) All kinds of soil
(iii) Sandy soil                                   (c) Dark in colour
(iv) Middle layer of the soil                (d) Small particles and packed tight                                                                                                                                               (v) Clayey soil                                  (e) Lesser amount of humus

Describe the function of the heart.

Salma takes 15 minutes from her house to reach her school on a bicycle. If the bicycle has a speed of 2 m/s, calculate the distance between her house and the school.

Draw the circuit diagram to represent the circuit shown in Fig.14.21.