Parenchyma cells are

The dead element present in the phloem is

Name the tissue which:
$(i)$ allows aquatic plants to float.
$(ii)$ provides flexibility to plants.

$A$ long tree has several branches. The tissue that helps in the sideways conduction of water in the branches is

Explain the significance of the following:
$(a)$ Hair-like structures on epidermal cells
$(b)$ Epidermis has a thick waxy coating of cutin in desert plants
$(c)$ Small pores in the epidermis of a leaf
$(d)$ Numerous layers of epidermis in cactus
$(e)$ Presence of a chemical suberin in cork cells.

What is the difference between sclerenchyma and collenchyma?