Assertion (A): Epithelial tissues form protective layers. Reason (R): They are highly vascularized to transport nutrients. MCQ with Answer and Explanation

Explanation:
Salivary amylase (ptyalin) hydrolyzes starch into maltose and dextrins, initiating carbohydrate digestion. The reason explains the presence of amylase in saliva.

Explanation:
The root is divided into zones. The root hair zone contains epidermal extensions (root hairs) that vastly increase surface area, making it the primary region for water and mineral absorption. The zone of cell division (meristematic zone) is at the very tip, where active mitosis occurs; the zone of elongation is where cells expand in length, pushing the root tip forward. The root cap is a thimble-like structure protecting the delicate apical meristem as it pushes through soil. Thus, statements 1 and 3 are correct.

Explanation:
The placenta is the organ that attaches to the uterine wall and facilitates exchange of nutrients, oxygen, and wastes between mother and fetus. The umbilical cord connects the fetus to the placenta. The amnion forms a protective fluid-filled sac.