Download The World of Microbes

The World of
Microbes
A study on the stuff that
makes us sick.
What are Bacteria?
 Bacteria
 They
 They
are microscopic organisms
are prokaryotic
have a single cell with no true
nucleus
What are bacteria?
 They
have no extra organelles, like
other cells do
 Some
bacteria have flagella, or whip
like features that help them to move
A bacteria cell
Types of Bacteria
 Most
bacteria come in one of three
basic shapes: coccus, rod or
bacillus, and spiral.
Coccus shaped bacteria
 The
cocci are spherical or oval
bacteria
Bacilli, or Rod-shaped bacteria
 Bacilli
are rod-shaped bacteria
Spiral shaped bacteria
 Spirals
come in one of three forms, a
vibrio, a spirillum, or a spirochete
Rod-shaped bacteria
More bacteria…
 Because
prokaryotes have a single,
circular chromosome rather than the
sets of chromosomes found in the
more familiar eukaryotes, mitosis
does not occur in prokaryotes.
Instead, most replicate by a process
of binary fission.
What are viruses?
A
virus is a microscopic organism
that causes other living things to
become sick.
 Viruses
depend on host cells that
they infect to reproduce.
What are viruses?
 When
it comes into contact with a
host cell, a virus can insert its
genetic material into its host, literally
taking over the host's functions.
So, how do viruses reproduce?
 they
cannot reproduce without the
help of a living cell (the host cell.)
 Viruses
are made up of genetic
materials (DNA or RNA) surrounded
by a protective coat of protein. They
are capable of latching onto cells and
getting inside them.
Types of viruses
 In
humans, smallpox, the common
cold, chickenpox, influenza, shingles,
herpes, polio, rabies, Ebola (flesheating virus), and HIV (an
autoimmune disease) are examples
of viral diseases.
viruses
Ebola virus
HIV