Question

select the true statements. all four dna nucleotides have identical nitrogenous bases. all four dna nucleotides have identical 5 - carbon sugars. all four dna nucleotides have identical phosphate groups.

Explanation:

• Nitrogenous bases: The four DNA nucleotides have different nitrogenous bases (adenine, cytosine, guanine, thymine), so the statement "All four DNA nucleotides have identical nitrogenous bases" is false.
• 5 - carbon sugars: In DNA, all nucleotides have deoxyribose as the 5 - carbon sugar. So the statement "All four DNA nucleotides have identical 5 - carbon sugars" is true.
• Phosphate groups: The phosphate group in each nucleotide has the same chemical structure (\(-O - P - O-\) with appropriate charges). So the statement "All four DNA nucleotides have identical phosphate groups" is true.

Answer:

• B. All four DNA nucleotides have identical 5 - carbon sugars.
• C. All four DNA nucleotides have identical phosphate groups.