Questions and Answers
The prokaryotic cells that built stromatolites are classified as _____
The prokaryotic cells that were the first to add significant quantities of oxygen to Earth's atmosphere are classified as _____
Streptococcus pyogenes is classified with _____
Organisms that can cause nongonococcal urethritis are classified with _____
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The chemoheterotroph Proteus vulgaris is a rod-shaped bacterium classified with _____
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Spiral-shaped bacteria are likely to be placed with _____
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According to this phylogenetic tree, which of these pairs of prokaryotic subgroups share the most recent common ancestor?
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Which group was not described in Woese's tree of life analysis?
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What characteristics were used to classify organisms before Woese's tree of life analysis?
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Data showing that the Bacteria were the first lineage to diverge from the common ancestor of all living organisms suggest that the Archaea and Eukarya are more closely related to each other than they are to the Bacteria.
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Which of the following statements about phylogenetic trees is true?
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Which molecule did Carl Woese study to produce his tree of life?
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What is lateral gene transfer?
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Select the four statements that are true for bacteria in the genus Azotobacter.
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Study Notes
Prokaryotic Classification and Characteristics
- Cyanobacteria: Prokaryotic cells that build stromatolites and first introduced significant oxygen into Earth's atmosphere.
- Streptococcus pyogenes: Classified with gram-positive bacteria, associated with various infections.
- Chlamydias: Includes organisms that can cause nongonococcal urethritis.
- Proteobacteria: Contains chemoheterotrophic bacteria like Proteus vulgaris, which is rod-shaped.
- Spirochetes: Characterized by spiral-shaped bacteria.
Phylogenetics and Woese's Analysis
- Common Ancestors: Euryarchaeota and Crenarchaeota share the most recent common ancestor according to phylogenetic trees.
- Prokarya Group: Not included in Woese's tree of life analysis; classified organisms were Bacteria, Archaea, and Eukarya.
- Previous Classification: Organisms were previously classified based on the presence of a membrane-bound nucleus before the ribosomal RNA sequence analysis.
Molecular Biology Insights
- Ribosomal RNA (rRNA): Key molecule studied by Carl Woese to construct the tree of life.
- Lateral Gene Transfer: Refers to the physical transfer of genes between species in separate lineages, playing a role in genetic diversity.
Azotobacter Characteristics
- General Traits: Azotobacter are gram-negative, obligate aerobes, bacilli that can fix nitrogen.
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True Statements about Azotobacter:
- Have a relatively thin layer of peptidoglycan in their cell wall.
- Require O2 for cellular respiration.
- Capable of converting atmospheric nitrogen to ammonia.
- Exhibit rod-shaped morphology.
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Description
Test your knowledge on the classification and characteristics of prokaryotic organisms. This quiz covers important groups such as cyanobacteria, streptococcus, and proteobacteria, as well as insights from phylogenetics like Woese's analysis. Ideal for students studying microbiology.
