Explain the diversity found in the size,shape,and structure of cells.

(N/A) Cells exhibit great diversity in size,shape,and activities.
$1$. Size of the cell: Cells vary significantly in size. Mycoplasmas,the smallest cells,are only $0.1$ to $0.3 \mu m$ in length. Bacteria are $3$ to $5 \mu m$. The largest isolated single cell is the egg of an ostrich. Generally,the size of cells in multicellular organisms ranges from $5$ to $100 \mu m$. Some cells are exceptionally long,such as human nerve cells,which can reach up to $90 \ cm$ in length. Human red blood cells are about $7.0 \mu m$ in diameter.
$2$. Shape of the cell: Cells also vary greatly in their shape. They may be disc-like,polygonal,columnar,cuboid,thread-like,or even irregular (e.g.,amoeboid). The shape of the cell often correlates with the specific function they perform.