Microbiology: Taxonomy and Classification

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Questions and Answers

What is the science of classification of organisms that hopes to show relationships among organisms?

Genetics

Taxonomy (correct)

Phylogeny

Systematics

What is the main difference between classification and identification?

Classification is about naming, while identification is about grouping

Classification is about grouping, while identification is about naming

Identification is a broader term, while classification is more specific

Classification is a broader term, while identification is more specific (correct)

What is the name of the technique used to determine the susceptibility of bacterial strains to certain phages or bacterial viruses?

rRNA Sequencing

Polymerase Chain Reaction

Phage Typing (correct)

DNA Fingerprinting

What is the term for the evolutionary relationships and history among organisms?

Phylogeny Signup and view all the answers

Which of the following is NOT one of the 5 kingdoms based on nutrient procurement?

Eukarya Signup and view all the answers

What is the term for the study of the structure, behavior, and evolution of organisms?

Systematics Signup and view all the answers

What is the term for the proportion of guanine and cytosine bases in DNA?

GC content Signup and view all the answers

Which domain includes plants, animals, fungi, and protists?

Eukarya Signup and view all the answers

What is the primary purpose of biochemical tests in bacterial identification?

To determine the nutritional and physiological interaction of the organism with its environment Signup and view all the answers

What is the function of differential staining in bacterial identification?

To distinguish between different types of bacteria Signup and view all the answers

What is the purpose of a dichotomous key in bacterial identification?

To identify eukaryotes Signup and view all the answers

What is the significance of highly conserved sequences in bacterial genetic material?

They are found in all bacteria Signup and view all the answers

What is the purpose of the International Code for the Nomenclature of Bacteria?

To set out the rules for bacterial nomenclature Signup and view all the answers

What is the purpose of a clinical microbiology lab report form?

To report the results of microbiological tests Signup and view all the answers

What is the significance of the genus and species names in bacterial nomenclature?

The first name characterizes the genus and the second the species Signup and view all the answers

What is the purpose of family names in bacterial nomenclature?

To end in -aceae Signup and view all the answers

What is the first step in the classification of bacteria?

Grouping them into a hierarchic system based on phenotypic characteristics Signup and view all the answers

What is the basic unit of classification in bacteria?

Species Signup and view all the answers

How are family names of bacteria typically denoted?

They end in -aceae Signup and view all the answers

What is the role of chemical characteristics in bacterial classification?

It is growing in importance Signup and view all the answers

What is the significance of DNA-DNA hybrids in bacterial classification?

They provide information on the similarity of different bacteria Signup and view all the answers

What is the significance of GC content in bacterial classification?

It provides information on the evolutionary relationships of bacteria Signup and view all the answers

What is the significance of the sequence analysis of 16S/23S rRNA or rDNA in bacterial classification?

It provides information on the phylogenetic relationships of bacteria Signup and view all the answers

What is the main reason for the classification of bacteria being based on phenotypic characteristics?

Because little is known about the phylogenetic relationships of bacteria Signup and view all the answers

Study Notes

Taxonomy and Classification

Taxonomy includes two disciplines: classification and nomenclature
Classification is based on phenotypic characteristics (morphological, physiological, and chemical)
The basic unit of classification is the species
Similar and related species are classified in a single genus, and related genera are placed in a single family

Classification of Bacteria

Bacteria are grouped in the domain Bacteria
Within the domain, bacteria are further broken down into taxonomic groups (taxa) based on relationships and phylogenetic facts
Classification is often based on similarities among phenotypic characteristics (phenetic relationships)
Morphological, physiological (metabolic), and chemical characteristics are used in classification

Morphological Characteristics

Microscopic morphology: cell shape, size, arrangement, staining, capsule, spore morphology
Colonial morphology: colonial appearance, color, shape, texture, margin, elevation, etc.

Biochemical Tests

Fermentation/oxidation of carbohydrates
Enzyme activities
Metabolism of organic acids, lipids, proteins, and amino acids
pH or redox range of growth
Tolerance of chemical agents

Nomenclature

The rules of bacterial nomenclature are set out in the International Code for the Nomenclature of Bacteria
A species is designated with two Latinized names, the first of which characterizes the genus and the second the species
Family names always end in -aceae
Taxonomic names approved by the International Committee of Systematic Bacteriology are considered official

Hierarchy of Taxonomic Ranks

Species
Genus
Family
Order
Class
Division
Phylum
Kingdom
Domain

Phylogeny and Systematics

Shows evolutionary relationships and history among organisms
Uses rRNA sequencing or other sequence information to identify organisms
Goal is to identify all organisms by 2025

5 Kingdoms of Nutrient Procurement

Plantae: multicellular photoautotrophs
Animalia: ingestive
Fungi: absorptive
Protozoa: mostly single-celled
Prokaryotes: bacteria and archaea

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Description

This quiz covers the principles of taxonomy, classification, and nomenclature in microbiology, including the hierarchical system of classification based on phenotypic characteristics.