An enzyme works like a key to a lock. If it finds the right thing it can work.
Hope it helps.
Answer:
Option A , Genome
Explanation:
Microarrays that contains array of single stranded DNA are used to study thousands of gene expression for all the genes of a genome and are usually termed as DNA miscroarrays. These microarrays being single stranded allows attachment of complementary DNA strand to bind to their surface. The mRNA from the cell is extracted and converted into cDNA which is further used for DNA cloning.
Hence, option A is correct
Viruses need to be inside a living thing (of course the living thing has to have the right temperature which most living things do) . When they're inside a living thing they start injecting the host's cells with its DNA in order to make more copies of itself which allows the virus to spread. So basically viruses need to be inside something living.