Which of the following is NOT true about the structure of DNA?

• A. The backbone of DNA is made up of sugar and phosphate groups.
• B. DNA strands run parallel to each other.
• C. DNA is composed of two strands that form a double helix.
• D. The strands of DNA are held together by hydrogen bonds between complementary bases.

Answer: (B)

Verified step by step guidance

1. Understand the basic structure of DNA: DNA is composed of two strands that form a double helix. Each strand is made up of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base.
2. Identify the components of the DNA backbone: The backbone of DNA is made up of alternating sugar and phosphate groups. This structure provides stability and support to the DNA molecule.
3. Examine the orientation of DNA strands: DNA strands are antiparallel, meaning they run in opposite directions. One strand runs in the 5' to 3' direction, while the other runs in the 3' to 5' direction.
4. Explore how DNA strands are held together: The strands of DNA are held together by hydrogen bonds between complementary bases. Adenine pairs with thymine, and cytosine pairs with guanine.
5. Determine which statement is NOT true: Based on the understanding of DNA structure, identify that the statement 'DNA strands run parallel to each other' is incorrect, as DNA strands are antiparallel.