The cell of Microfossil

A great many microfossils are the product of singlecelled
(unicellular) organisms. A little knowledge of
these cells can therefore help us to understand their
way of life and, from this, their potential value to Earth
scientists. Unicells are usually provided with a relatively
elastic outer cell membrane (Fig. 1.1) that binds
and protects the softer cell material within, called the
cytoplasm (or protoplasm). Small ‘bubbles’ within the
cytoplasm, called vacuoles, are filled with food, excretory
products or water and serve to nourish the cell
or to regulate the salt and water balance. A darker,
membrane-bound body, termed the nucleus, helps to
control both vegetative and sexual division of the cell
and the manufacture of proteins. Other small bodies
concerned with vital functions within the cell are known
as organelles. The whip-like thread that protrudes
from some cells, called a flagellum, is a locomotory
organelle. Some unicells bear many short flagella, collectively
called cilia, whilst others get about by means
of foot-like extensions of the cell wall and cytoplasm,
known as pseudopodia. Other organelles that can occur
in abundance are the chromoplasts (or chloroplasts).
These small structures contain chlorophyll or similar
pigments for the process of photosynthesis.