Night blindness is caused by the deficiency of which vitamin? MCQ with Answer and Explanation

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.

Explanation:
Ethylene is a gaseous plant hormone that promotes fruit ripening (climacteric fruits like banana, apple), leaf abscission, and senescence. Auxin, gibberellin, and cytokinin primarily promote growth. Ethylene is used commercially to ripen fruits uniformly. It also stimulates the formation of abscission layers and inhibits stem elongation.

Explanation:
Blood group A has A antigens and anti-B antibodies. Group O has no antigens, AB is universal recipient, Rh incompatibility can cause erythroblastosis fetalis.