Chapter 10: Classification of Microorganisms

Question 1

-The science of classifying organisms
-Provides universal names for organisms

Answer 1

Taxonomy

Question 2

-Binomial nomenclature (genus + specific epithet)

-Escherichia coli
-Homo sapiens

Answer 2

Scientific Nomenclature

Question 3

Taxonomic Hierarchy

Answer 3

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

Question 4

A population of cells with similar characteristics

Answer 4

Prokaryotic species

Question 5

Grown in laboratory media

Answer 5

Culture

Question 6

Population of cells derived from a single cell

Answer 6

Clone

Question 7

Genetically different cells within a clone

Answer 7

Strain

Question 8

-Placing organisms in groups of related species
-Lists of characteristics of known organisms

Answer 8

Classification

Question 9

-Matching characteristics of an “unknown” organism to lists of known organisms
-Clinical lab identification

Answer 9

Identification

Question 10

Useful for identifying eukaryotes

Answer 10

Morphological characteristics

Question 11

Gram staining, acid fast staining

Answer 11

Differential staining

Question 12

Determines presence of bacterial enzymes

Answer 12

Biochemical tests

Question 13

-Involves combining a known antiserum plus unknown bacterium
-Relies on antigen-antibody reactions
-Can identify species and strains within species

Answer 13

Serology

Question 14

-A positive test produces a grainy appearance due to clumping (agglutination) of bacteria
-(Salmonella enterica – typhoid fever)

Answer 14

Slide agglutination test

Question 15

-Enzyme-linked immunosorbent assay
-Known antibodies
-Unknown type of bacterium
-Antibodies linked to enzyme
*Color change occurs in presence of antigen-antibody complex
*Used for HIV testing (note: HIV is virus)

Answer 15

ELISA

Question 16

-Proteins from known bacterium or virus separated by electrophoresis
-Proteins transferred to filter by blotting
-Patient’s serum washed over the filter
-If patient has antibodies toward any of the proteins they will bind
-Anti-human serum linked to an enzyme then washed over the filter
-Made visible as color band on the filter after adding enzyme substrate

Answer 16

Western blotting

Question 17

-A test for determining which phages a bacterium is susceptible to
-A drop of each phage type is placed on the bacterial cells
-Phages that infect and lyse bacterial cells create clearings in the bacterial growth called plaques

Answer 17

Phage typing

Question 18

-Sources of food-associated infections can be traced by _____ _____
-A patient’s infected surgical would can be traced to operating surgeon or nurses

Answer 18

Phage typing

Question 19

Used to identify bacteria in a sample without culturing the bacteria

Answer 19

Flow Cytometry

Question 20

-Fluid containing bacteria is forced through a small opening
-Differences in electrical conductivity between species identifies bacteria
-Fluorescence used to detect some species
-Cells selectively stained with antibody plus fluorescent dye

Answer 20

Flow Cytometry

Question 21

-DNA fingerprinting
-DNA of two microorganisms fragmented by restriction enzymes and separated by electrophoresis producing DNA fingerprint
-“Fingerprints” compared for similarities/ differences

Answer 21

Genetics

Question 22

-Are maps that show evolutionary relationships among organisms (clado- means branch)
-rRNA sequences are used are used since most microorganisms do not leave fossils

Answer 22

Cladograms