Which kingdom includes organisms with cell walls made of chitin and a heterotrophic mode of feeding?

• A. Fungi
• B. Protists
• C. Monera
• D. Archaea

Answer: (A)

Chitin in cell walls and heterotrophic feeding define fungi. Chitin is a sturdy, nitrogen-containing polymer that strengthens fungal cell walls, a hallmark of this kingdom. Fungi obtain nutrients by absorbing them: they secrete enzymes to decompose organic matter and then take up the resulting nutrients, rather than photosynthesizing. This combination of chitin-rich walls and absorptive, heterotrophic nutrition fits fungi, whereas Protists have varied wall materials and nutrition, and Monera and Archaea rely on different cell wall components (peptidoglycan or other polymers) and do not use chitin.