2. They are prokaryotic organisms(kingdom
monera)without cell defined organelles like
mitochonmdria,golgi bodies, ER etc.
Microscopic, unicellular may occur single or
in aggregate to form colonies.
Possess rigid cell wall, made of
peptidoglycan and lipopolysaccharides.
No well defined nucleus ,DNA is not
enclosed in nuclear membrane
Ribosome's are scattered in cytoplasm and
are of 70S type.
Most are heterotrophic some are
autotrophic possesses bacteriochlorophyll.
3. Motile bacteria possess one or more flagella
They cannot pass through bacterial filters.
Common method of multiplication is binary
fission.
True sexual reproduction is lacking.
4. Smallest unicellular organisms that are
obligate intracellular. They are most
primitive org.infecting man.
Obligate intracellular
Possess either DNA or RNA ,but never both
Can pass through bacterial filters
Cant grow on artificial cell free media.
Multiply by complex method.
Do not have proper cellular organization.
Don’t have cell wall or cell membrane or
cellular organelles.
They lack they enzyme necessary for
synthesis of nucleic acid and protein.
5. Not susceptible to antibacterial antibiotics.
They are enclosed in a protective envelope.
They do not respire, do not metabolize and
do not grow but they do reproduce
They are considered both as living and non
living things, as viruses are inactive when
they are present outside of host cells and
are active in side of host cells. As they make
use of raw materials and enzymes of the
host cell to reproduce.
In the year 1897, a scientist named
Beijerinck discovered and coined the term
virus. The term virus is derived from Latin
word-“virus” means poison.
6. They can only be seen with an electron
microscope
Their size ranges from 20 nanometers
(parvovirus) to 400 nanometers (poxvirus).
7. ‘fungus’ Greek “mykes” meaning mushroom.
Their study is called mycology.
Eukaryotic and possess all eukaryotic cell
organelles such as mitochondria .
Possess rigid cell wall, composed of Chitin, beta-
glucans and other polysaccharides.
Cell membrane contains ergosterol instead of
cholesterol.
Fungi can be unicellular, multicellular, or
dimorphic, which is when the fungi is unicellular or
multicellular depending on environmental
conditions.
Lack chlorophyll
Divide asexual or sexual means by producing
spores.
8. Fungi like to be in a moist and slightly acidic
environment; they can grow with or without
light or oxygen
