The digestion of the food in humans begins in the mouth. In the mouth, the salivary amylase enzyme digests and breaks down a small amount of the starch present in the food. The digestion process begins right in the mouth. and continues till the intestine. The carbohydrates (starch) are the ones whose digestion starts in the mouth.
Hence, the blanks can be filled with 'mouth and amylase' respectively.
Because they take up both parts of traits so that makes it group to similar organisms
The answer is fixed interval
I hope that helped
