Download Biology 11 Notes: Kingdom Monera

Biology 11 Notes: Bacteria
FYI
April 2011
– Prokaryotes outnumber all eukaryotes combined!
General Characteristics:
-lack a nucleus and membrane bound organelles (therefore prokaryotic)
-cell wall
-microscopic / unicellular (some colonies)
-asexual reproduction
-roughly 4000 classified species (estimated to be around 400 000 to 4 million species!)
*Only a minority of bacteria cause disease… majority are essential to all life on earth.
Diagram:
capsule: protective layer outside the cell wall, only on some bacteria
pilli: bridging structures
Classifying Bacteria:
I) Based on Origin
Archaebacteria – ancient bacteria (live in extreme environments)
Eubacteria – true bacteria
II) Based on Shape
III) Based on Cell Wall
Gram + have a thick cell wall composed of mostly peptidoglycan (stain violet)
Gram – have an outer cell membrane which hides the cell wall’s peptidoglycan (stain pink)
Life Process
Nutrition
Bacteria Life Processes Review:
Notes
Heterotrophs:
-parasites (live in or around another organism) or
-saprophytes (decomposers)
Autotrophs:
-photosynthetic autotrophs (eg. Cyanobacteria)
or
-chemosynthetic autotrophs
Most are:
-aerobic (require O2)
Respiration
Some are:
-facultative anaerobes (use O2 if available but can undergo aerobic
respiration)
or
-obligate anaerobes (grow slowly or can be killed if O2 is present)
Asexual reproduction (see figure below)
-aka. binary fission
-cell division (but not technically Mitosis… why??)
-example of exponential population growth
Reproduction
Conjugation (see figure below)
-exchanging of genetic material
-simple sexual reproduction
Spore formation
-some species can form an endospore in unfavourable conditions
(dormant phase)
Binary Fission
Conjugation