Micro –organisms are of four types: bacteria [TB,
typhoid, cholera, diphtheria, and plague], algae, protozoa
[dysentery, malaria] and fungi. Virus [jaundice] reproduces
only inside host organisms.
Lactobacillus multiplies in milk and
turns it into curds.
Amoeba is a single celled organism. It
has pseudopodia which are finger like projections. These
capture the food particle and put it in the food vacuole.
After digestion the leftover matter is expelled by the
vacuole. Amoeba reproduces asexually by binary fission.
Hen egg is also single cell.
Bacteria living in our mouth break food
and leave acid that causes tooth decay. Tooth decay is
caused when the pH of mouth goes below 5.5. Calcium
phosphate, insoluble in water and is the hardest substance
in the body but at pH 5.5 it starts dissolving.