Frogs exchange gases through their skin and the lining of their mouths. This exchange of gases is referred to as respiration. During the larval stage in frogs development, it lacks functional lungs but they can take in oxygen through gills which are in process of metamorphosis.
The gills take in oxygen when water is being passed over them. Once lungs are mature, they lose their gills and are able to bring in oxygen through lungs.
They rely on lungs to breath when they are active and they need more oxygen than what skin respiration alone can provide.
Although they have oxygen, most of their respiration occurs through the skin.
I think the correct answer from the choices listed above is option B. Yawning is a fixed action pattern type of innate behavior. This behavior is an instinctive behavioral sequence and it inevitably runs into completion which means it cannot be stopped. Hope this answers the question.
Answer: The fundamental sugar unit for carbs is usually glucose. To address your question, starch digestion is required because enzymes and transport molecules require tiny, regular molecules to work with, and glucose is the foundation of most carbohydrate metabolism.
Explanation: