Question

Hydathodes are present on the
A Upper surface of leaf
B Lower surface of leaf
C Tip of vein of leaf
D Base of veins of leaf

Answer 1

Hint:A hydathode is a type of pore, commonly found in angiosperms, that secretes water through pores in the epidermis of leaf margin, typically at the tip of a marginal tooth or serration.

Complete answer:
Hydathode pores located on the tip of leaf veins at the margins of leaves. Just below the hydathode pore are present a number of thin-walled loosely packed cells, called as epithem, which covers the blind or dead end of tracheid.
Hydathodes are mainly found in aquatic plants and in some herbaceous plants growing in moist places. They probably evolved from modified stomata and are connected to the plant vascular system by a vascular bundle.
Hydathodes are made of a group of living cells with numerous intercellular spaces filled with water, but few or no chloroplasts, and represent modified bundle-ends.
These cells open out into one or more sub-epidermal chambers. These, in turn, communicate with the exterior through an open water stoma.

Hence the correct answer is option “C”.

Note:The loss of water in the form of liquid through the hydathodes is known as the guttation. The Hydathodes are also known as the water stomata; they are found at the tips of the veins of the leaves. The Hydathodes do not have guard cells; they are pores in the epidermis which is followed by large intercellular space.