Girth of stem increases due to

Give the characteristics and role of the following:
$(i)$ Cutin
$(ii)$ Suberin
$(iii)$ Sclereids

The water conducting tissue generally present in gymnosperms is

$(a)$ Give reasons for the following:
$(i)$ Multicellular organisms are considered more efficient.
$(ii)$ Sclerenchyma cells have a narrow lumen.
$(iii)$ Epidermis is thicker in desert plants though it is usually single layered.
$(b)$ Name the following:
$(i)$ Tissue that occurs in specific regions of growth.
$(ii)$ Tissue present at the growing tips of stems and roots.
$(iii)$ Tissue at the base of the leaves or internodes on twigs.
$(iv)$ Basic packing tissue in the form of a few layers of cells.

When observed under a microscope,small pores are seen in the epidermis of the leaf. What are these pores called? Write two functions of these pores.

$(a)$ Identify the given figures.
$(b)$ State in brief their structure.
$(c)$ Describe the role performed by the two.