Double-stranded DNA can adopt various forms based on conditions like hydration, ionic strength, and chemical environment. Which of the following statements correctly matches the properties of B-form and C-form DNA?
1
B-form DNA has a right-handed helix with a major groove well-defined and a minor groove narrower and deeper, while C-form DNA is a left-handed helix that requires a high salt concentration for stabilization.
2
B-form DNA is the most common form under physiological conditions, with a right-handed helix and approximately 10.5 base pairs per turn, while C-form DNA is also right-handed but has about 9.3 base pairs per turn and requires a higher level of humidity.
3
B-form DNA has a left-handed helix and is primarily found under conditions of low ionic strength, while C-form DNA has a right-handed helix, is stabilized at high salt concentrations, and has about 11 base pairs per turn.
4
B-form DNA has a right-handed helix with approximately 9 base pairs per turn and is stable under physiological conditions, while C-form DNA, characterized by a left-handed helix, occurs rarely and only in specific sequences of DNA.