Answer:
That B-form DNA helices have a pitch of approximately 34 angstroms
Step-by-step explanation:
Rosalind Franklin was an X-ray crystallographer whose work contributed to the discovery of the molecular structure of DNA molecule by Watson and Crick. B-form DNA is the most common form of DNA, which consists of a right-handed double helix. B-form DNA was discovered by Watson and Crick based on the X-ray diffraction image of DNA (popularly known as image 51) obtained by Franklin. The pitch refers to the distance after every 10 base pairs along the DNA helix for one complete double-helix turn. This distance in the B-DNA helix is 34 Ångströms (i.e., 3.4 nanometers).