A researcher is studying a newly discovered bacterium that thrives in anaerobic conditions and produces methane as a byproduct of its metabolism. This organism lacks a true nucleus and membrane-bound organelles. Based on these characteristics, into which domain of life would this organism most likely be classified?
- ABacteria
- BEukarya
- CArchaea
- DFungi
Show answer & explanationAnswer & explanation
Correct answer: C. Archaea
The organism described is a single-celled prokaryote that thrives in extreme conditions (anaerobic, methane production) and lacks a true nucleus. These characteristics are hallmarks of Archaea, which are known for inhabiting extreme environments and having unique metabolic pathways. While Bacteria are also prokaryotes, they generally differ in their cell wall composition and metabolic pathways, and are not typically methane producers in this manner.
Why the other options are wrong
- A. While Bacteria are prokaryotes, the methanogenesis and extreme anaerobic conditions are more characteristic of Archaea.
- B. Eukarya possess a true nucleus and membrane-bound organelles, which this organism lacks.
- D. Fungi are eukaryotes and possess a true nucleus and membrane-bound organelles.
Characteristics of Archaea
Archaea are a domain of single-celled microorganisms that are prokaryotes, meaning they lack a cell nucleus and other membrane-bound organelles. They are often found in extreme environments and possess unique biochemical features.
- Prokaryotic (no nucleus or membrane-bound organelles)
- Often extremophiles (thrive in harsh conditions)
- Unique cell wall composition (not peptidoglycan like bacteria)
- Distinct rRNA sequences
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