Question

Tick the correct options
1 Aquatic plants and animals use............to respire.
a dissolved oxygen
b dissolved carbon diodde
c dissolved nitrogen
d dissolved water
2 When it rains heavily, earthworms come out of the soil because.............
a they like rain b no air is left in the soil for them
c no food is left in the soil for them d soil is wet
3. For burning of fuels, which of the following gases is necessary?
a oxygen
b nitrogen c carbon dioxide d hydrogen
4 Balance of oxygen and carbon dioxide in air is maintained by............
(a) plants only
b) animals only
(c) both plants and animals
(d) moving vehicles
​

Answer 1

Answer:

1) The water of ponds, lakes, rivers and seas has some dissolved air in it. So, the animals and plants which live in water use the air dissolved in water for breathing (or respiration). The animals and plants which live in water use the oxygen dissolved in water for breathing (or respiration).

2)An earthworm breathes oxygen by absorbing it through its moist skin. It likes damp soil, but if the rain is very heavy, the oxygen in the water-logged soil may run out. Then the worm has to come up into the air to breathe. On top of the wet ground, the worm can breathe and wriggle along.

3)oxygen

hope it is helpful