question_answer

  Give reasons: (i) Plants look green. (ii) The respiratory surface of earthworm is its skin. (iii) Nutrition is necessary for an organism. (iv) We boil the leaf in alcohol when we are testing it for starch.

Answer:

                  At the top of the trachea (or wind pipe) there is a flap of cartilage called the function of epiglottis is to cover the mouth of trachea (or wind we swallow food so that the food may not enter the trachea (or wind pipe).