David Anderson, age 14, of Downey, Calif .,
Are there male and female bacteria?
David has observed that certain willows have male and female catkins and hollies have male and female flowers. Since bacteria are plants, it is natural to wonder whether they too have these divisions. Until a few years ago, the answer would have been a definite, No. But scientists are always learning new things. Lately they have learned that there are a few bacteria which multiply as parents. It may be unscientific to do so, but let 1s call these little parents male and female.
Bacteria, of course, are single celled plants. We call them microorganisms because these tiny living things can be studied only under a microscope. Most of them are colorless blobs and in order to study them they must be stained. They are measured by the angstrom unit which is about one 2500th part of an inch. Bacteria come in assorted sizes. Most measure about one angstrom, some measure only half and certain whoppers measure 20 angstroms.
Small as it is, a bacterium is a well organized unit. It has a cell wall which lets in nutritious liquids and keels out certain harmful chemicals. The cell wall is filled with clear protoplasm the jelly¬like material which fills all living plant and animal cells. Somewhere in the protoplasm there is at least one small granular nucleus. This single cell can take in food, use it, get rid of waste material and carry on all the processes necessary for life.
It can even multiply. In this matter, most bacteria still follow the oldfashioned scientific theory. They multiply by dividing. When conditions are right, the average bacterium divides into a pair of identical twins.
This magic begins in the cell nucleus. Here are the chromosomes which contain the genes. These sub microscopic factors hold the secrets which make a bacterium what it is from generation to generation.
Recent studies show that in perhaps a billion bacteria, a pair of they, will merge and become parents. In this process, the two cell muclei join and then separate, which means that there is a rearrangement of the genes. The new generation, then, is likely to have new qualities. As they multiply, we get a new strain of bacteria, with qualities different from their ancestors.
Sometimes a wonder drug, say penicillin, fails to destroy all the bacteria it should. Germs seem to be getting smarter, or immune to these drugs. This could be because they got only enough of the drug to make them sick, whereupon they built up resistance, much as we build up resistance to the summer sun with a sun tan. On the other hand, it could be because of the new strains produced by those rare parent bacteria. Suppose among billions of germs, one new strain just happened to be proof against penicillin. The drug would destroy all the rest and leave this one strain to multiply and bacteria multiply at a very great rate.