Mark the following statements as True or False. Correct the false statements.

(a) Oxygen breaks down glucose outside the cells of organisms.


(b) Frogs can breathe through their skin as well as lungs.


(c) Insects have spiracles on the lower surface of the body.


(d) Exhaled air has more percentage of CO2 than inhaled air.


a) FALSE. The breakdown of glucose into carbon dioxide and energy is done using oxygen inside the cell. This process is known as respiration.

b) TRUE. Likewise humans frogs also can respire through lungs. In addition to lungs frogs can also respire through their skin which is thin, moist and slimy and help in easy gaseous exchange.


c) FALSE. Spiracles are the tiny pores present in the insects like cockroaches which help in gaseous exchange. These small spiracles are present on the lateral body (sides) of the organism.


d) TRUE. The percentage of CO2 in inhaled air is 0.04% whereas in exhaled air it is 4.4%. Therefore, we can say that exhaled air has more percentage of carbon dioxide than in the inhaled air.


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