$(a)$ 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.

(N/A) $(i)$ Multicellular organisms are composed of millions of different types of cells which form specific tissues to perform specific functions more efficiently. There is a division of labour amongst cells,making these organisms more efficient.
$(ii)$ Sclerenchyma cells have a narrow lumen due to the heavy deposition of lignin on their cell walls. These walls become so thick that there is hardly any internal space left inside the cell.
$(iii)$ The epidermis is thicker in desert plants to prevent water loss through transpiration. This is achieved by the presence of a thick,waxy,water-resistant coating of cutin.
$(b)$ $(i)$ Meristematic tissue
$(ii)$ Apical meristem
$(iii)$ Intercalary meristem
$(iv)$ Parenchyma