Classification of Microbes

Question 1

binomial nomenclature system

Answer 1

Two names, Genus and species: Genus species

Question 2

Summarize the taxonomic hierarchy from domain to species

Answer 2

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 3

Taxonomy

Answer 3

the branch of science concerned with classification, especially of organisms

Question 4

Taxon

Answer 4

Subdivision of classification (Kingdom, Phylum, Class, etc.)

Question 5

Phylogeny

Answer 5

the study of the evolutionary history of organisms

Question 6

Culture

Answer 6

Microorganisms that grow and multiply in a container of culture medium

Question 7

Clone

Answer 7

A population of cells arising from a single parent cell

Question 8

Strain

Answer 8

Genetically different cells within a clone. See serovar

Question 9

Serovars

Answer 9

A variation within a species; also called serotype

Question 10

Protist

Answer 10

Term used for unicellular and simple multicellular eukaryotes; usually protozoa and algae

Question 11

Bacteria Characteristics

Answer 11

Prokaryotic; cell wall contains peptidoglycan; membrane lipids are composed of straight carbon chains attached to glycerol by ester linkage; first amino acid in protein synthesis is Formylmethionine; susceptible to antibiotics; has an rRNA loop and a common arm of tRNA; reproduce through binary fission

Question 12

Archaea Characteristics

Answer 12

Prokaryotic; cell wall varies in composition but contains no peptidoglycan; membrane lipids are composed of branched carbon chains attached to glycerol by ether linkage; first amino acid in protein synthesis is methionine; resistant to antibiotics; does not have an rRNA loop or a common arm of tRNA; reproduce through binary fission

Question 13

Eukarya Characteristics

Answer 13

Eukaryotic; cell wall varies in composition but contains carbohydrates; membrane lipids are composed of straight carbon chains attached to glycerol by ester linkages; first amino acid in protein synthesis is methionine; no rRNA loop but does have a common arm of tRNA; reproduce sexually or asexually

Question 14

Describe how a newly discovered microbe can be classified by DNA sequencing

Answer 14

DNA sequencing determines the precise order of nucleotides, and the resulting sequence can be compared to known microbial DNA sequences to identify the organism’s closest relatives.

Question 15

Describe how a newly discovered microbe can be classified by DNA fingerprinting

Answer 15

DNA fingerprinting focuses on confirmation of the identity of individual organisms, and compares the DNA of the organism to known species

Question 16

Describe how a newly discovered microbe can be classified by NAAT

Answer 16

Nucleic acid amplification tests like PCR can create many copies of a small sample of DNA, and therefore make it easier to study and classify.

Question 17

Describe how microorganisms can be identified by nucleic acid hybridization

Answer 17

There are many different methods of nucleic acid hybridization, but they all involve exposing a DNA sample to a DNA probe with a tag, which can find and label any DNA sequences complementary to its DNA.

Question 18

Describe how microorganisms can be identified by Southern blotting

Answer 18

Southern blotting is a type of nucleic acid hybridization in which DNA fragments are separated by size by gel electrophoresis, then transferred to a membrane, then exposed to a labeled DNA probe with a radioactive, fluorescent, or chemical tag.

Question 19

Describe how microorganisms can be identified by DNA microarrays

Answer 19

DNA microarrays are a type of nucleic acid hybridization in which a chip with specific complementary DNA sequences is mixed with a DNA sample that has been fluorescently dyed. A machine is used to measure the intensity of the fluorescence at each sequence on the chip.

Question 20

Describe how microorganisms can be identified by ribotyping

Answer 20

Ribotyping specifically looks at the rRNA genes, through gel electrophoresis and analysis of the banding pattern. Useful when figuring out domain or phylum; but less useful for anything more specific.

Question 21

Differentiate a dichotomous key from a cladogram

Answer 21

A dichotomous key is an identification key based on successive questions; each question has two possible answers. A cladogram is a map that shows evolutionary relationships among organisms (based on rRNA sequences).