Question

Watson and Crick model of DNA is a

• A. $B$-form DNA with a spiral length of $34\mathring{A}$ and a diameter of $20\mathring{A}$
• B. $A$-form DNA with a spiral length of $15\mathring{A}$ and a diameter of $20\mathring{A}$
• C. $Z$-form DNA with a spiral length of $34\mathring{A}$ and a diameter of $20\mathring{A}$
• D. $B$-form DNA with a spiral length of $28\mathring{A}$ and a diameter of $14\mathring{A}$

Answer 1

The correct option is A $B$-form DNA with a spiral length of $34\mathring{A}$ and a diameter of $20\mathring{A}$

• The model of DNA was given by Watson and Crick in the year 1953. It is the hereditary molecules that are responsible for carrying the characters from parents to offspring.
• The DNA is in the $B$-form that shows left-handed coiling.
• The spiral length is $34\mathring{A}$ and its diameter of $20\mathring{A}$. One spiral turn has $10$ base pairs.
  Thus the correct answer is option A.