Question

Which of the following general statements about the structure of DNA is true?

• A. The Hydrogen bonds connecting base pairs exist in a polar environment.
• B. Both major and minor grooves are formed between the Phosphate-sugar backbone.
• C. The same C and N atoms are present in each groove.
• D. The amount of energy required to break down the AT and GC pairs is the same.

Answer 1

The correct option is A The Hydrogen bonds connecting base pairs exist in a polar environment.

• The DNA double helical structure has two different environments. The Nitrogenous bases have an aromatic ring structure and are hydrophobic and interact with each other through base pair stacking interactions.
• At the same time, the back bone of DNA formed by Phosphodiester bonds is hydrophilic and interacts with water.
• The Nitrogenous bases of one nucleotide chain form Hydrogen bonds with the Nitrogenous bases present directly opposite them on the other chain.
• The Hydrogen bonds are formed in polar aqueous environment.
• The Adenine base pairs with Thymine with two Hydrogen bonds and Guanine base pairs with Cytosine with three Hydrogen bonds.

So, the correct answer is option A.