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 RNA molecules (like tRNA) can also have complex three - dimensional shapes, but the key difference in terms of the given options is the single - stranded nature of RNA compared to the double - stranded nature of DNA.

Answer:

B. a single strand