Morphology of Cells – Size, Shape and Structure

The shape, size and structure of cells are often related to the specific function they perform.

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Read First –

Cell – The Fundamental unit of Life – Summary

Cell – Introduction

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Cell Shape

The shape of a cell may be variable (e.g. W.B.C. or leucocyte ; Amoeba have changing shapes) or fixed and peculiar for a particular type of cell (e.g. Human R.B.C. are circular and biconcave).

Both plant and animal cells show diverse shapes such as –

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Cell Size

The size of the cells vary greatly (0.1mm to 18 cm).

• Smallest cell – Cells of Mycoplasma gallisepticum (0.1mm)
• Longest cell –  Nerve cells in Humans (1m long)
• Largest cell –  Egg of an Ostrich (central yellow sphere) (18cm)

Cells are generally very small and are seen only with microscope.

The small size of the cell provides –

• 1 mm = 10-6 meter or 10-3 millimeter
• Larger an organism, greater the number of cells in the body.

(a) large surface area – It ensures greater diffusion of substances in and out of the cell.
(b) easy repair of any damage to the cell.

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Cell Structure

All cells have three basic parts –

1. Outer membrane – Cell membrane / Plasma membrane and Cell wall (present only in plant cells)
2. Cytoplasm
3. Nucleus

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 Read Also –

Life before  a Nucleus

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Read Next –

Outer membrane – Cell membrane / Plasma membrane and

Cell wall (present only in plant cells)