(N/A) $\rightarrow$ Frogs respire on land and in water by two different methods.
$\rightarrow$ In water,the skin acts as an aquatic respiratory organ,known as cutaneous respiration. Dissolved oxygen in the water is exchanged through the skin by diffusion.
$\rightarrow$ On land,the buccal cavity,skin,and lungs act as respiratory organs.
$\rightarrow$ Respiration by lungs is called pulmonary respiration. The lungs are a pair of elongated,pink-coloured,sac-like structures present in the upper part of the trunk region. Air enters through the nostrils into the buccal cavity and then into the lungs.
$\rightarrow$ During summer sleep (aestivation) and winter sleep (hibernation),gaseous exchange takes place exclusively through the skin.