What are decomposers in the detritus food chain primarily composed of?

Fungi and bacteria

The correct answer is Option (3) - Fungi and bacteria.

Decomposers in the detritus food chain are primarily composed of fungi and bacteria. These heterotrophic organisms play a crucial role in breaking down dead organic matter or detritus in the ecosystem.

Fungi and bacteria are saprotrophs, also known as saprophytes or saprobes. They obtain their energy and nutrients by decomposing dead plant material, animal remains, and other organic waste. Decomposers secrete digestive enzymes that break down complex organic compounds into simpler, inorganic materials. They then absorb these simple, inorganic substances to meet their energy and nutrient requirements.

Decomposers are vital for nutrient cycling and the recycling of organic matter in ecosystems. Through their activities, they release nutrients back into the environment, making them available for uptake by plants and other organisms.

While producers (option a), herbivores (option b), and carnivores (option d) are important components of the ecosystem, decomposers, primarily composed of fungi and bacteria, specifically play the role of breaking down dead organic matter in the detritus food chain.