Identifying and Classifying Microorganisms

Taxonomy

The science that studies organisms and arranges them into groups.

Taxa

The different groups or categories into which organisms are classified.

Identification

The process of characterizing organisms in order to group them.

Classification

The arrangement of organisms into similar or related groups.

Nomenclature

The system of assigning names to organisms.

Whittaker's 5 Kingdom Classification

The classification scheme devised by _____ in the 1960s, which includes the kingdoms Plantae, Fungi, Animalia, Protista, and Monera.

Three Domain System

The current classification scheme based on evolutionary relatedness, including the domains Bacteria, Archaea, and Eukarya.

Bacteria

Prokaryotic organisms with no membrane-bound organelles, unique ribosomal RNA sequences, and containing peptidoglycan.

Archaea

Prokaryotic organisms with no membrane-bound organelles, unique ribosomal RNA sequences, and no peptidoglycan.

Eukarya

Organisms with eukaryotic cell structure, including a nucleus and other membrane-bound organelles, unique ribosomal RNA sequences, and no peptidoglycan.

Hierarchical Scheme of Classification

The _____, including domains, kingdoms, phyla, classes, orders, families, genera, and species.

Phenotype

The observable characteristics of an organism, used in identifying and categorizing microorganisms.

Genotype

The genetic makeup of an organism, used in identifying and categorizing microorganisms.

Microscopic Morphology

The size, shape, and staining characteristics of microorganisms, used in their identification.

Culture Characteristics

The growth, color, appearance, smell, and other characteristics of microorganisms in culture, used in their identification.

Metabolic Capabilities

The biochemical tests used to determine the metabolic capabilities of microorganisms, such as fermentation.

Serological Characteristics

The use of antibodies to detect specific proteins and polysaccharides in microorganisms, used in their identification.

Proton Profile

The use of mass spectrometry to determine the chemical composition of a sample, used in the identification of microorganisms.

Nucleic Acid Amplification Tests (NAATs)

Methods to detect specific nucleotide sequences unique to a given species or related group of microorganisms.

DNA Probes

Tagged pieces of DNA used to identify specific segments of DNA in unknown microorganisms.

Sequencing Ribosomal RNA Genes

Determining the nucleotide sequence of ribosomal RNA molecules or the DNA that encodes them, used in identifying microbes.

Whole Genome Sequencing

Sequencing the entire genome of an organism, used in studying outbreaks and predicting antibiotic resistance.

Strains

Groups of related isolates or strains within a species, which may vary in minor ways.

Binomial Nomenclature

The naming system used in taxonomy, where each species is identified by two names:the genus and species names.

Bacteria

Single-celled prokaryotes with specific shapes, rigid walls containing peptidoglycan, and the ability to multiply via binary fission.

Archaea

Prokaryotic organisms with specific shapes, rigid cell walls without peptidoglycan, and the ability to grow in extreme environments.

Eukarya

Organisms with eukaryotic cell structure, including organelles, a nuclear membrane, and the ability to engage in mRNA splicing.

Algae

Photosynthetic eukaryotes, single or multicellular, belonging to the kingdom Protista.

Fungi

Diverse group of eukaryotes, including yeasts and molds, single or multicellular.

Protozoans

Diverse group of single-celled aquatic or terrestrial organisms, complex and large, belonging to the kingdom Protista.

Mammals

Multicellular organisms belonging to the kingdom Animalia, characterized by the presence of mammary glands and hair or fur.

Helminths

Parasitic worms that live at the expense of the host, including roundworms, tapeworms, and flukes.

Viruses

Acellular entities consisting of nucleic acid surrounded by a protein coat, requiring a host for replication.

Viroids

Simpler than viruses, consisting of short RNA without a protective coat, causing plant diseases.

Prions

Infectious proteins that can cause fatal neurodegenerative diseases in humans and animals.