CELL — STRUCTURE AND FUNCTIONS

A tissue is a group of similar cells performing a specific function.

Neuron

A white blood cell (WBC) in human blood is another example of a single cell which can change its shape. But whileWBC is a cell, amoeba is a full fledged organism capable of independent existence.

e the projections of varying lengths protruding out of its body. These are called pseudopodia (pseudo : false; podia : feet),

Trillion = 1,000,000,000,000 1012

Billion = 1,000,000,000 109

Ten lakhs = 10,00,000 Million = 1,000,000 106

The single-celled organisms are called unicellular (uni : one; cellular : cell) organisms. A single-celled organismperforms all the necessary functions that multicellular organisms perform.

Organisms made of more than one cell are called multicellular (multi : many; cellular : cell) organisms.

Ostritch egg