•Prokaryotic cells are about 10 times smaller than eukaryotic cells•Prokaryotic cells lack many cell structures such as organelles •All prokaryotes are microorganisms, but only some eukaryotes are
Not independently living - acellular organismsØMuch simpler than cells- basically a small amount of DNA or RNA wrapped in protein and sometimes by a lipid membraneØIndividuals are called a virus particle or virion ØDepend on the infected cell’s machinery to multiply and disperse
Coined the term cell
•Pasteurization•The Germ Theory of Disease•Vaccination
verified the germ theory
What is the germ theory of disease?
lMicrobes (germs) cause disease and specific microbes cause specific diseases.
. Who proved this theory?
lRobert Koch in the late 1870's.
Ø3. What disease was he studying?
lanthrax - disease of cattle/sheep
Ø4. What was his experimental method?
lHe observed that the same microbes were present in all blood samples of infected animals. He isolated and cultivated these microbes (Bacillus anthracis ). He then injected a healthy animal with the cultured bacteria & that animal became infected with anthrax & its blood sample showed the same microbes as the originally infected animals.
Ø5. What did his experiments prove?
lParticular microbes cause particular diseases.
Ø6. What are Koch's 4 Postulates?
l1. The causative agent must be present in every individual with the disease.l2. The causative agent must be isolated & grown in pure culture (how did he invent pure cultures? with Frau Hesse's help, he developed the agar plate method.)l3. The pure culture must cause the disease when inoculated into an experimental animal.l4. The causative agent must be reisolated from the experimental animal & reidentified in pure culture.
classifying living things
Carl von Linné
binomial system of nomenclature
genus name followed by the species name
the degree of relatedness between groups of living things
evolution- Two preconceptions:
•All new species originate from preexisting species
•Closely related organisms have similar features because they evolved from a common ancestor