With reference to the food chains in ecosystems, which of the following kinds of organism is / are known as decomposer organism/organisms?
Select the correct answer using the codes given below.(2013)
a) 1 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
Viruses are a type of parasites and cannot survive without hosts.