Question

With the help of examples, describe how cells vary in terms of shape, size, and number.

Answer 1

Cells vary in shapes, sizes and number;

• Cells can have different shapes depending on their function. For example, nerve cells carrying messages between different parts of the body are elongated while muscle cells are thin and long as they help in movement.
• Cell sizes vary from a micrometre to few centimeters. Bacteria are the smallest cells ranging from size 0.1 to 0.5 micrometres. The Ostrich’s egg is the largest cell of 170 millimeter in diameter.
• Unicellular organisms are those whose body consists of a single cell, which performs all functions of the body. E.g. Amoeba, Paramecium and bacteria. Some organisms are multicellular, whose body consists of many cells. E.g., animals and most plants. Thus, number of cells can vary in various organisms.