Classification logic: What is the correct relationship between “fungi” and “heterotrophic organisms” when considering how these groups are defined biologically?
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AAll members of heterotrophic organisms are also members of fungi, but not all fungi are heterotrophs
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BAll members of fungi are also members of heterotrophic organisms, but not all heterotrophs are fungi
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CAll heterotrophs are fungi and all fungi are heterotrophs
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Dnone of the above
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EAll heterotrophs are plants
Answer
Correct Answer: All members of fungi are also members of heterotrophic organisms, but not all heterotrophs are fungi
Explanation
Introduction / Context:Understanding set relationships prevents logical fallacies in biology. “Fungi” is a specific kingdom; “heterotrophs” describes a nutritional mode found in many kingdoms.
Given Data / Assumptions:
- Fungi are heterotrophic, absorbing organic nutrients.
- Heterotrophy also occurs in animals, many protists, and some bacteria.
- Therefore, the set of heterotrophs is broader than the set of fungi.
Concept / Approach:Set inclusion: Fungi ⊂ Heterotrophs, while Heterotrophs ⊄ Fungi. This captures the correct one-way inclusion and excludes equivalence or reverse inclusion.
Step-by-Step Solution: Define fungi by kingdom and heterotrophy by nutrition. List other heterotrophs (animals, protozoa, many bacteria). Conclude fungi are a subset of heterotrophs, not vice versa. Choose the statement expressing “all fungi are heterotrophs, but not all heterotrophs are fungi.”
Verification / Alternative check:Examples: humans (heterotrophs) are animals, not fungi; yeasts are fungi and heterotrophs.
Why Other Options Are Wrong:
- Reverse inclusion or equality: Contradicts observed diversity of heterotrophy across kingdoms.
- Heterotrophs are plants: Plants are primarily photoautotrophs.
Common Pitfalls:Equating nutritional modes with taxonomic ranks.
Final Answer:All members of fungi are also members of heterotrophic organisms, but not all heterotrophs are fungi.