In DNA structure, what is the overall shape of the DNA molecule called?

• A. Alpha helix
• B. Double helix
• C. Beta-pleated sheet
• D. Single helix

Answer: (B)

Verified step by step guidance

1. Understand that DNA is a molecule that carries genetic information in living organisms.
2. Recall that the structure of DNA was discovered by Watson and Crick, who described its shape based on experimental data.
3. Recognize that DNA consists of two strands twisted around each other, forming a specific three-dimensional shape.
4. Identify that this shape is called a 'double helix' because it involves two helical strands coiled together.
5. Note that other options like 'alpha helix' and 'beta-pleated sheet' refer to protein structures, not DNA.