Question

which example is always single - stranded?
○ dna and rna
○ mrna
○ dna
○ dsrna

Explanation:

mRNA (messenger RNA) is always single - stranded. DNA is usually double - stranded (although some viruses have single - stranded DNA). dsRNA (double - stranded RNA) is double - stranded. The option “DNA and RNA” is incorrect as DNA is not always single - stranded and RNA has different forms (like dsRNA which is double - stranded).

Answer:

mRNA