Lecture 2: The Microorganisms
1. Three Kingdoms
a) Plants have cell walls, not actively motile, have chlorophyll, energy source
b) Animals No chlorophyll in cells, get energy from organic materials.
c) Protists unicellular, lack differentiation of cells and tissues.
2. The Tree of Life
Archaea is the closest to the beginning of life because they are at the
bottommost part of the tree.
RNA sequences tell where life falls on the tree.
The “String” is the lowest level of branches off of other branches.
In this class, we will mostly be studying bacteria and some eucaryota, not
3. Microorganisms can be Eucaryotic, Procaryotic, or Viruses.
Eucaryotes have a true nucleus with a membrane
Procaryotes have no nuclear membrane, all DNA is intertwined within the
cell. All bacteria are procaryotes.
Viruses are noncellular.
Bacteria are 110 micrometers in size.
Viruses are smaller, at about 100 nanometers.
Chloroplasts are about the same size as bacteria