The cell wall of plants is mainly composed of: MCQ with Answer and Explanation

Explanation:
In a chloroplast, the thylakoids are flattened membranous sacs that are arranged in stacks like coins, which are called grana (singular: granum). The stroma is the fluid-filled matrix surrounding the thylakoids. The thylakoid membranes contain the pigments necessary for the light reactions of photosynthesis.

Explanation:
The liver produces bile, metabolizes nutrients, detoxifies, stores glycogen, and synthesizes plasma proteins. Insulin is from pancreas.

Explanation:
The stem is characterized by the presence of nodes, which are the junctions where leaves and buds arise, and internodes, the segments between two nodes. While some stems are modified to grow underground (like potatoes or onions) for storage or perennation, the primary and most common form of the stem is aerial, growing above the ground. Statements 1 and 2 are correct.