WEEK 5: SS1 BIOLOGY THIRD TERM
GROWTH OF MICRO-ORGANISMS Micro-organisms' growth refers to an increase in population size, i.e, an increase in t he number of cell s. Microorganisms grow and multiply by binary fission. For example, a bacterium can divide every 20 minutes and this time interval is known as the doubling/generation time . This generation time depends on environmental factors like the availability of food, space, and adequate temperature. BENEFICIAL EFFECTS OF MICRO-ORGANISMS Many micro-organisms are beneficial in the following ways: 1. In nature, they function as decomposers and primary producers. Many saprophytic bacteria and fungi convert dead remains of organisms and their wastes into humus , which improves soil fertility. 2. In medicine, microbes are useful in the manufacture of drugs, vaccines and antibiotics which help in curing many human diseases e.g Penicillin - an antibiotic obtained from Penicillium notatum (...