Which kingdom contains organisms that are mostly decomposers and do not perform photosynthesis?

• A. Animalia
• B. Plantae
• C. Protista
• D. Fungi

Answer: (D)

Decomposition and how organisms obtain energy differ among kingdoms. Fungi live by breaking down dead or decaying material outside their bodies with enzymes and then absorbing the nutrients. They do not have chlorophyll and cannot carry out photosynthesis, so they rely on external digestion rather than making their own sugars. That combination—being non-photosynthetic and functioning mainly as decomposers—fits fungi.

Plants are built to capture light and convert it into chemical energy, so they are photosynthetic rather than decomposers. Animals generally obtain energy by consuming other organisms rather than breaking down dead matter on a large scale, though some scavenging occurs. Protists include a wide range, from algae to amoebae; some are photosynthetic, others absorb nutrients or decompose, but the group as a whole is not defined by being mostly decomposers.

Thus, the kingdom that contains organisms that are mostly decomposers and do not perform photosynthesis is fungi.