Question

structure of dna: the double helix
label this diagram, showing part of the dna double helix. you can add extra labels
nucleotides
dna

Explanation:

1. The unlabeled box pointing to the connecting dashed lines between complementary base pairs refers to Hydrogen Bonds—these are the weak bonds that hold the two DNA strands together by pairing complementary nitrogenous bases.
2. The unlabeled box pointing to the repeating sugar-phosphate backbone (the connection between the pentagon and blue circle) refers to Sugar-Phosphate Backbone (the pentagons are deoxyribose sugar, blue circles are phosphate groups, forming the structural framework of each DNA strand).
3. Additional key labels for the diagram:

• Blue circles: Phosphate Group
• Red/orange pentagons: Deoxyribose Sugar
• Colored rectangles: Nitrogenous Bases (complementary pairs, e.g., green-purple, blue-yellow represent A-T or G-C pairs)
• The blue box at the top right: Base Pair (labels the paired complementary bases)

Answer:

• Box pointing to dashed lines: Hydrogen Bonds
• Box pointing to sugar-phosphate link: Sugar-Phosphate Backbone
• Additional labels:
• Blue circles: Phosphate Group
• Red/orange pentagons: Deoxyribose Sugar
• Colored rectangles: Nitrogenous Bases
• Top blue box: Base Pair