With reference to the food chains in ecosystems, which of the following kinds of organism is/are known as decomposer organism/organisms? 1. Virus 2. Fungi 3. Bacteria Select the correct answer using the codes given below.

1. Decomposer organisms play a crucial role in ecosystems by breaking down dead organic matter (detritus) such as dead plants, animals, and waste products, returning essential nutrients to the soil or water. 2. Fungi (2) are major decomposers. They secrete enzymes that break down complex organic compounds, like lignin and cellulose in wood, into simpler substances that they can absorb. Examples include mushrooms and molds. 3. Bacteria (3) are also principal decomposers. They are ubiquitous and break down a vast array of organic materials through various metabolic processes. 4. Viruses (1) are obligate intracellular parasites. They require living host cells to replicate and do not carry out decomposition of dead organic matter in the environment. They are not considered decomposers in the ecological sense. 5. Therefore, Fungi and Bacteria are known as decomposer organisms.