Living organisms verses inanimate objects. Characteristics of living organisms. Maintaining life processes. Normal vital functions Body systems operating to obtain oxygen, nutrients, Responding to environment and adapt to environmental stimuli Maintaining life in disease Treatments
Characteristics of living organisms
Supporting life processes
The microorganisms shown here are: A, the bacterium Escherichia coli; B, a photosynthetic cyanobacterium; C, a fungus; D, Ebola virus; E, the protozoan malaria parasite. (Sources: B, Mike Clayton; C-E, CDC). Note that the scale on each of these pictures is different.
Microorganisms played an important role in removing many of the pollutants released during the Exxon Valdez oil spill in Prince William Sound. Interestingly, microbes were not added to the site, but the clean-up relied on bacteria from that environment. A nutrient solution was sprayed onto the oil to encourage the growth of oil-degrading microbes. Though this was one of the more successful methods used to clean up the oil, but no treatment removed all of the pollutants.
Typical cell structure of a eubacterium
Gram-negative Pseudomonas aeruginosa bacteria (pink-red rods).
Gram stain for anthrax
Malaria is caused by four species of protozoan parasites Plasmodium falciparum
Plants – cells contain chloroplasts and carry out photosynthesis,
i.e. convert sunlight CO2 and H20 to sugars
Invertebrates – do not have a backbone
Vertebrates do have a backbone
Binary fission, or prokaryotic fission, is the form of asexual reproduction and cell division used by all prokaryotic and some single-celled eukaryotic organisms. This process results in the reproduction of a living prokaryotic cell by division into two parts which each have the potential to grow to the size of the original cell.
The cell cycle. Image from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com)
* Embryonic stem cell come from early embryos – are totipotent
* umbilical cord stem cells are multipotent.
* Adult stem cells are multipotent