Question

maps (diagram with labels: guanine, cytosine, uracil, ribose - phosphate backbone, deoxyribose - phosphate backbone, hydrogen bonds between base pairs) what are the main differences between rna and dna? select all that apply. rna contains weak hydrogen bonds between its phosphate groups and 5 - carbon sugars. rna does not contain thymine. instead, it has a nitrogenous base called uracil. dna is usually double - stranded, while rna is usually single - stranded. rna contains the 5 - carbon sugar ribose instead of deoxyribose.

Explanation:

1. Analyze the first option: RNA's backbone is formed by covalent bonds (phosphodiester bonds) between phosphate groups and 5 - carbon sugars, not hydrogen bonds. So this option is incorrect.
2. Analyze the second option: DNA has thymine (T), while RNA has uracil (U) instead of thymine. This is a correct difference.
3. Analyze the third option: DNA is typically double - stranded (double helix), and RNA is usually single - stranded. This is a correct difference.
4. Analyze the fourth option: DNA has deoxyribose as its 5 - carbon sugar, and RNA has ribose. This is a correct difference.

Answer:

B. RNA does not contain thymine. Instead, it has a nitrogenous base called uracil.
C. DNA is usually double - stranded, while RNA is usually single - stranded.
D. RNA contains the 5 - carbon sugar ribose instead of deoxyribose.