Chapter 1 Handout

What are microorganisms

What are microorganisms

organisms too small to be seen clearly by the unaided eye

what are 2 characteristics of microorganisms

<1mm, some macroscopic

simple construction, lack differentiated tissues

what are the two divisions of microbes

cellular and acellular

what are the four members of cellular microbes

fungi

protists

bacteria

archaea

what are the four members of acellular microbes

viruses,

viroids

satellites

prions

what term refers to the aerial or above ground parts of plants colonized by microbial communities

phyllosphere

what term refers to microbial communities inhabiting the root surface and soil zone around the root

rhizosphere

what term refers to the microbial communities residing within plant tissues

endosphere

what class are fungi in?

eukaryotesw

what class are protists in

eukaryotic

what class are bacteria

prokaryotic

what class are archaea

prokaryotic

central dogma of biology

DNA to RNA to proteins

what is the RNA world hypothesis

life on Earth began with a simple RNA molecule that could copy itself without help from other molecules

what is the endosymbiotic theory

a proto or cyanobacterium was engulfed by a primordial eukaryotic cell and interacted, evolving so that the cyanobacterium became mitochondria

what is microbial phylogeny

the study of the manner in which various groups of microorganisms are genetically related

universal phylogenetic trees

not only spans all extant life, but its root and earliest branchings represent stages in the evolutionary process before modern cell types had come into being

what are the two types of phylogenic trees

unrooted, rooted

what is spontaneous generation theory

idea that life can develop from nonliving or decomposing matter disproved by Francesco Redi

what is pathogen disease theory

diseased caused by pathogens

what is cell theory

living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells

what are Koch’s postulates

1. Microorganism must be present in all cases of the disease.

2. Microorganism must be isolated and grown in pure culture.

3. Pure culture must cause the same disease when inoculated into a healthy host.

4. Microorganism must be re-isolated from the newly infected host and identified as the same microorganism.