Science-- Things Essential for life

 

              

(Class-4)

  Chapter no - 1

Questions/answers

Q-1 why does the Earth not become as cold as moon at night?

Ans - The earth does not become as cold as moon moon at night because Earth’s moon has no atmosphere to hold in heat at night or prevent the surface from getting so hot during the day.

Q-2 Why do we need oxygen for breathing?

Ans- we need oxygen to breath to get energy from our food. Oxygen helps in burn food to produce energy, this energy is used for our growth and to repair damaged part of our body.

Q-3 what things do plants need to make their food?

Ans - plants need carbon dioxide, water and sunlight to make their food.

Q-4 why do living beings need water?

Ans - Human beings and animals need water to help them digest food. The chemical changes in the body can only take place in the presence of water. Plants need water to help them in growth and produce food in their leaves.

Q-5 which things maintain just the right amount of warmth on the earth?

Ans- All our life  functions depend on the right amount of warmth. Air and water maintain just the right amount of warmth on the earth to maintain life.