Florida Biology EOC Practice Test

The correct answer is Fungi. This kingdom is predominantly composed of multicellular organisms that are eukaryotic, meaning their cells contain a nucleus and membrane-bound organelles. Fungi are primarily heterotrophic, absorbing nutrients from organic matter, which positions them as decomposers in many ecosystems. This role is crucial for nutrient cycling as they break down dead organic material.

Additionally, the cell walls of fungi are made of chitin, a characteristic that distinguishes them from other kingdoms such as plants, which have cell walls made of cellulose, and bacteria, which have cell walls made of peptidoglycan. Unlike organisms in the Animalia kingdom, fungi do not ingest food like animals but rather secrete enzymes to digest organic material externally and then absorb the resulting small molecules.

This specialization in structure and function allows fungi to thrive in diverse environments and contribute significantly to ecosystem health.