Difficulty: Easy
Correct Answer: Chloroplasts
Explanation:
Introduction / Context:
Fungi are eukaryotes with distinctive cellular features. Distinguishing them from plants, animals, and protists requires understanding which organelles and macromolecules they possess or lack.
Given Data / Assumptions:
Concept / Approach:
Fungi have mitochondria, nuclei, and cytoskeletons characteristic of eukaryotes. Their plasma membranes contain ergosterol rather than cholesterol (in animals). Cell walls comprise chitin, glucans, and mannans. Critically, fungi lack chloroplasts and do not perform photosynthesis; this separates them from plants and many algae.
Step-by-Step Solution:
List structures present in fungi: mitochondria, chitinous wall, spores, ergosterol membranes.
Identify the organelle absent in fungi: chloroplasts.
Select “Chloroplasts” as the correct answer.
Confirm that other listed items are indeed fungal features.
Verification / Alternative check:
Antifungal agents targeting ergosterol (e.g., azoles, polyenes) highlight the unique fungal membrane composition compared with plants and animals.
Why Other Options Are Wrong:
Common Pitfalls:
Assuming all eukaryotes with cell walls photosynthesize; fungi do not.
Final Answer:
Chloroplasts.
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