Answer: Phosphorous
Explanation:
Phosphorous can be used to label Nucleic acid. Nucleic acids can be modified or labelled using tags .
Some common materials or substances that can be used to label nucleic acids are flurophore, enzymes, radioactive phosphorous, biotin et cetera.
The nucleic acid of virus is labelled using phosphorous. When this virus will infect the host cell then nucleic acids will be seen separately.
In my opinion mixed layers would be the best choice
The word is <u>an individual</u> of a species
