Differentiate between chlorenchyma and aerenchyma.

Cork cells are made impervious to water and gases by the presence of

$(a)$ 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.

Skeletal muscles are mostly attached to

The water conducting tissue generally present in gymnosperms is

Survival of plants in terrestrial environment has been made possible by the presence of