Answer:
A virus is a tiny infectious biological agent that can only replicate or duplicate inside the host cell. These infectious agents can infect all different types of living organisms ranging from animals and plants to microorganisms and archaea and bacteria.
Virions are ineffective particle or form of the virus outside of the host cell, with RNA or DNA and a protein capsid.
The main role of these infectious agent virions is to transfer the DNA or RNA genome from itself to the cell of host and expressed the gene which means produce proteins from the genome transferred to the host cell.
Genetics is what I would say
As per I know there is no scenario which describes fungi as a decomposer.
▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️
Algae are not plants, animals or fungi. They belong to Kingdom Protista, a diverse group of single-celled eukaryotes.
Protists have their own kingdom because many species share some characteristics of plants, animals or fungi.
Algae belong to the group of plant-like protists.
They are autotrophs that fulfill the role of producer in ecosystems because they make their own food via photosynthesis, like plants.
▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️▪️