Class 7 Science - Chapter Nutrition in Plants NCERT Solutions | Choose the correct option from the follo

Show with the help of a sketch that the plants are the ultimate source of food.

Tick the correct answer:

(a) Amarbel is an example of:
     (i) autotroph (ii) parasite (iii) saprotroph (iv) host

(b) The plant which traps and feeds on insects is:
     (i) Cuscuta (ii) china rose (iv) pitcher plant (iv) rose

Why do organisms need to take food?

Fill in the blanks:
(a) Green plants are called _________________ since they synthesise their own food.
(b) The food synthesised by the plants is stored as _________________.
(c) In photosynthesis solar energy is captured by the pigment called ___________.
(d) During photosynthesis plants take in ______________________ and release __________________.

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.

Distinguish between a parasite and a saprotroph.

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

How would you test the presence of starch in leaves?

Mark ‘T’ if the statement is true and ‘F’ if it is false:
(i) Carbon dioxide is released during photosynthesis. (T/F)
(ii) Plants which synthesise their food themselves are called saprotrophs. (T/F)
(iii) The product of photosynthesis is not a protein. (T/F)
(iv) Solar energy is converted into chemical energy during photosynthesis. (T/F)

Match the items given in Column I with those in Column II:
Column I                          Column II
Chlorophyll                       Bacteria
Nitrogen                            Heterotrophs
Amarbel                            Pitcher plant
Animals                             Leaf
Insects                              Parasite

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.

Study the following statements about ozone:
(a) It is essential for breathing of living organisms.
(b) It is used to disinfect water.
(c) It absorbs ultraviolet rays.
(d) Its proportion in air is about 3%.

Which of these statements are correct?
(i) (a), (b) and (c)
(ii) (b) and (c)
(iii) (a) and (d)
(iv) All four

The rear view mirror of a car is a plane mirror. A driver is reversing his car at a speed of 2 m/s. The driver sees in his rear view mirror the
image of a truck parked behind his car. The speed at which the image of the truck appears to approach the driver will be

(i) 1 m/s            (ii) 2 m/s
(iii) 4 m/s          (iv) 8 m/s

Micro-organisms act upon the dead plants to produce
(i) sand     (ii) mushrooms     (iii) humus     (iv) wood

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?

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

Zubeda made an electric circuit using a cell holder shown in Fig. 14.4, a switch and a bulb. When she put the switch in the ‘ON’ position, the bulb did not glow. Help Zubeda in identifying the possible defects in the circuit.

David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m. If he moves 1 m towards the mirror, then the distance between David and his image will be

(i) 3 m        (ii) 5 m
(iii) 6 m      (iv) 8 m

Which of the following statements is not correct?

(i) Forests protect the soil from erosion.
(ii) Plants and animals in a forest are not depedent on one another.
(iii) Forests influence the climate and water cycle.
(iv) Soil helps forests to grow and regenerate

Outline your role as an active citizen in relation to sanitation.

Fig. 13.15 shows the distance-time graph for the motion of two vehicles A and B. Which one of them is moving faster?

                           Fig. 13.15 Distance-time graph for the motion of two cars