What is the term used to describe the overall shape or arrangement of a DNA strand?

• A. Double helix
• B. Triple helix
• C. Beta sheet
• D. Alpha helix

Answer: (A)

Verified step by step guidance

1. Understand that the question is asking for the term that describes the overall shape or arrangement of a DNA strand.
2. Recall that DNA is composed of two strands twisted around each other, forming a specific three-dimensional structure.
3. Recognize that the term 'double helix' refers to this structure where two strands wind around a common axis.
4. Note that 'triple helix' would imply three strands, which is not the typical structure of DNA.
5. Understand that 'beta sheet' and 'alpha helix' are terms related to protein secondary structures, not DNA.