Question

which structural characteristic is seen in rna but not in dna?
double strands
a single strand
chains of nucleotides
a helical shape

Explanation:

DNA is typically double - stranded (double helix structure), while RNA is usually single - stranded. Both DNA and RNA are made of chains of nucleotides. DNA has a helical shape (double - helix), and some forms of RNA (like tRNA) can also have complex three - dimensional shapes that may involve helical regions.

Answer:

a single strand