What Do These Pictures Have in Common?
gov.mb.ca
k8science.org
gsbs.utmb.edunuclearfamilywarhead.com
ViroidsConsist of short,
fragments of single-stranded RNA.
Only found in plants (so far).
Can interfere with plant’s metabolism, resulting in the plant being stunted or killed.
Ex. Potato spindle tuber
Left: normal potatoes; Right – infected potatoeswww.unece.org
Prokaryotic Cells
Yersinia pestis – Bubonic Plague. science.nationalgeographic.com
Clostridium botulism. www.nih.gov
Prokaryotic Cell Size and ShapeProkaryotic cells are
much smaller than eukaryotic cells (about the size of mitochondria)
Prokaryotes have three typical shapes:
http://www.bio.miami.edu/~cmallery/150/proceuc/c8.27x3.bact.shapes.jpg, http://sharon-taxonomy2009-p2.wikispaces.com/Archaea
Bacterial Cell WallGram-positive
Bacteria Thick layer of
peptidoglycan (60-100%)
Gram-negative BacteriaThin layer of
peptidoglycan (10-20%)Has outer membrane
composed of mostly lipids (80-90%)
Gram-positive Bacteria
Gram-negative Bacteria
pathmicro.med.sc.edu
Gram Stain Results
Gram-positive bacteria stains violet to blue.
Gram-negative bacteria stains pink to red.
homepage.ntlworld.com
Cyanobacteria
Anabaena. http://www.biologie.uni-hamburg.de/b-online/fo42/anabaena.jpg
Oscillatoria. http://t2.gstatic.com/images?q=tbn:LsEmj27QxYGiHM:http://botit.botany.wisc.edu