Frogs are carnivores, mice are herbivores. Compare frog or mouse heart and skeletal muscle. Both muscle types are striated, but the heart beats continuously without tiring easily. LM, TEM 7. Compare frog small intestine before and after metamorphosis.
Tadpoles have a diet very different from adults.
LM, TEM, SEM 8. Frogs and mice have different reproductive strategies. Frog eggs are several thousand times larger than mouse eggs. Compare frog and mouse cerebral or cerebellar cortex. Neural tissue is complex and requires special techniques to see adequately.