2. Classification
• Biologists have long organized living things into large groups called
kingdoms
• There are six of them:
• Archaebacteria
• Eubacteria
• Protista
• Fungi
• Plantae
• Animalia
3.
4. Common characteristics used for comparison among
living organisms
1. Cell type – 2 kingdoms are prokaryotic; 4 kingdoms are
eukaryotic
2. Cell wall – 4 of the 6 kingdoms have a cell wall
3. Body type – unicellular vs. multicellular
4. Nutrition – autotrophic vs. heterotrophic
5. Reproduction – sexual vs. asexual
5. Some recent findings…
• In 1996, scientists decided to split Monera into two groups of bacteria:
Archaebacteria and Eubacteria
• Because these two groups of bacteria were different in many ways scientists
created a new level of classification called a DOMAIN
• Now we have 3 domains
1. Bacteria
2. Archaea
3. Eukarya
6.
7. The Domain Archaea
• “ancient” bacteria
• Some of the first archaebacteria were discovered in Yellowstone National
Park’s hot springs and geysers
• Prokaryotes are structurally simple, but biochemically complex
9. Basic Facts
• They live in extreme environments (like hot springs or salty lakes)
• Normal environments (like soil and ocean water)
• All are unicellular (each individual is only one cell)
• No peptidoglycan in their cell wall
• Some have a flagella that aids in their locomotion
10.
11. Cont………
• Have ribosomes similar to eukaryotes
• Have unique lipids in their plasma (cell) membranes
• Have some genes that resembles that of eukaryotes
• Usually are not Pathogenic
• But lives in Extreme environments
12. Some weird things about this kingdom…
• Most don’t need oxygen to survive
• They can produce ATP (energy) from sunlight
• They can survive enormous temperature extremes
• They can survive high doses of radiation (radioactivity)
• They can survive under rocks and in ocean floor vents deep below the ocean’s
surface
• They can tolerate huge pressure differences
17. Characteristics of Eubacteria
• Prokaryotic
• Lack mitochondrions or chloroplasts
• Have a rigid cell wall made of peptidoglycan
• Flagella, if present, are made of single filament of the protein flagellin
• Cell membrane composed of a phospholipid bilayer that lacks cholestrol and
steroids
18. Cont………
• No mitosis - mostly asexual reproduction
• Many eubacteria form spores, resistant to dehydration and most
temperatures
• When there is no food and can last up to 50 years
• All eubacteria are either spirilla (spiral shaped), bacilli (rod shaped), or
cocci (spherical)
20. Classified on the basis of mode of Energy
Consumption
• Photosynthesizers
• Chemoautotrophs
• Heterotrophs
21. Photosynthesizers
• A significant fraction of the world’s photosynthesis is carried out by
bacteria
• Cyanobacteria are blue-green bacteria that contain chlorophyll in their
cell membrane
• Cyanobacteria are thought to have made the Earth’s oxygen atmosphere
23. Chemoautotrophs
• Breakdown chemicals found in the soil; they use those chemicals for
nutrition
• The bacteria’s waste products act as fertilizer and helps with agriculture
• A handful of soil can have up to 10 billion bacterial organisms
25. Heterotrophs
• Most types of Eubacteria are heterotrophic
• Together with fungi, they serve as primary decomposers for the environment
by releasing nutrients back to the soil after living things have died
26. Pathogenic Bacteria
• Our body is a treasure chest of wealth just waiting to be discovered by
bacteria
• Bacteria have evolved various ways of entering your body and taking what
they need in order to survive
• In some cases, the competition for the resources in your body can result in
you becoming ill
27. Bacteria are harmful in two ways:
• 1 - Bacteria can metabolize their host by using different parts of the body
as their food source
• Tuberculosis is a less common bacterial infection that attacks the lungs of
humans
• Mycobacterium tuberculosis is the bacteria that uses the lung tissue as a
food source
• The warm, moist environment allows the bacteria to reproduce and
populate the lungs
29. • 2- Bacteria cause disease by secreting chemical compounds called toxins
into their environment
• Humans are most affected when food is not properly prepared. Food
poisoning is the common name given to people who get severely sick
after eating something that wasn’t cooked well
• Most types of toxin bacteria can be killed by boiling water and cooking
foods at recommended temperatures
• Kitchen and surface antibacterial products also help in ridding our house
of these relentless pests
30. Characteristics
Archaea Bacteria
Ribosomes • Present • Present
Introduction • The Archaea constitute a domain or kingdom of
single-celled microorganisms
• These microbes are prokaryotes, meaning that they
have no cell nucleus or any other membrane-bound
organelles in their cells
• Bacteria constitute a large domain of prokaryotic
microorganisms
• Typically a few micrometres in length, bacteria
have a number of shapes, ranging from spheres
to rods and spirals.
Cell wall • Pseudopeptidoglycan • Peptidoglycan / Lipopolysaccharide
Habitat
• extreme and harsh environments like hot springs,
salt lakes, marshlands, oceans, gut of ruminants and
humans
• ubiquitous and are found in soil, hot springs,
radioactive waste water, Earth's crust, organic
matter, bodies of plants and animals etc.
Growth &
Reproduction
• Archae reproduce asexually by the process of
binary fission, budding and fragmentation.
• Eubacteria reproduce asexually through binary
fission, budding, fragmentation, but eubacteria
have the unique ability to form spores to remain
dormant over years atrait that is not exhibited by
Archae.
