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Ch. 11 - The Prokaryotes: Domains Bacteria and Archaea
Tortora - Microbiology: An Introduction 14th Edition
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398Not the one you use?Change textbook
Chapter 11, Problem 5

Which of the following terms is the most specific?
a. bacillus
b. Bacillus
c. gram-positive
d. endospore-forming rods and cocci
e. anaerobic

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1
Step 1: Understand the concept of specificity in microbiological terms. Specificity refers to how narrowly a term defines a group of organisms. The more specific a term, the fewer organisms it includes.
Step 2: Analyze each option: 'bacillus' (lowercase) generally refers to any rod-shaped bacterium, which is a broad morphological category.
Step 3: 'Bacillus' (capitalized and italicized) refers to a specific genus of bacteria, which is a taxonomic category more specific than shape or physiological traits.
Step 4: 'gram-positive' describes a broad group of bacteria based on their cell wall staining properties, which includes many genera and species.
Step 5: 'endospore-forming rods and cocci' and 'anaerobic' describe physiological or morphological traits that can apply to multiple genera, so they are less specific than a genus name.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Taxonomic Hierarchy and Specificity

Taxonomic hierarchy organizes living organisms into nested groups from broad to specific, such as domain, kingdom, phylum, class, order, family, genus, and species. The more specific a term, the lower it is in this hierarchy. For example, a genus name like Bacillus is more specific than a general shape or physiological trait.
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Scientific Nomenclature and Formatting

Scientific names of organisms follow binomial nomenclature, where genus and species names are italicized, with the genus capitalized. The term 'Bacillus' italicized refers to a genus, which is more specific than common descriptive terms like 'bacillus' (a shape). Proper formatting indicates a taxonomic rank rather than a general characteristic.
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Microbial Morphology and Physiology Terms

Terms like 'bacillus' (rod-shaped), 'gram-positive', 'endospore-forming', and 'anaerobic' describe morphology or physiological traits. These are broader categories that can apply to many different genera or species, making them less specific than a taxonomic genus name.
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