How does a one celled animal move around?
We share our wonderful world with a vast assortment of one celled animals. Most of them are too small to be seen without the help of a magnifying lens. But various types are as different from each other as lobsters and tigers. Each type has its own ways of coping with life. Biologists have classified about 20,000 one celled animals. Each is a protozoan of the phylum Protozoa, a scientific term meaning “first life.” The assorted protozoa are certainly the world’s smallest and simplest animals and most likely some of their ancestors were among the first animals to live upon the earth. More than two billion years ago, some of these remote ancestors lived in the ancient fresh water seas. And most of their small descendants still prefer life in the water. A few manage to make a living in the moisture of soggy soil. Others live as parasites in the juicy tissues of living plants and animals. It is, of course, much easier for such small bodies to move in water than on dry land. They can depend
