Which nitrogenous base pairs with guanine in DNA?

Which nitrogenous base pairs with guanine in DNA?

• A. Deoxyribose
• B. Ribose
• C. Thymine
• D. Cytosine

Answer: (D)

In DNA, nitrogenous bases pair in specific ways, following the rules of base pairing. Guanine, a purine base, pairs with cytosine, which is a pyrimidine base, through three hydrogen bonds. This complementary pairing is critical for the structure and function of DNA, ensuring that the genetic information is accurately replicated and maintained during cell division. The relationship between guanine and cytosine is fundamental in forming the DNA double helix structure, and their pairing contributes to the overall stability of the DNA molecule. The bonding between these two bases helps hold the two strands of DNA together, essential for the integrity of the genetic blueprint. Other options do not represent a nitrogenous base that pairs with guanine. Deoxyribose and ribose are sugars that are components of DNA and RNA, respectively, but they are not nitrogenous bases. Thymine, while a nitrogenous base in DNA, pairs with adenine rather than guanine. Thus, the correct pairing with guanine in DNA is indeed cytosine.

In DNA, nitrogenous bases pair in specific ways, following the rules of base pairing. Guanine, a purine base, pairs with cytosine, which is a pyrimidine base, through three hydrogen bonds. This complementary pairing is critical for the structure and function of DNA, ensuring that the genetic information is accurately replicated and maintained during cell division.

The relationship between guanine and cytosine is fundamental in forming the DNA double helix structure, and their pairing contributes to the overall stability of the DNA molecule. The bonding between these two bases helps hold the two strands of DNA together, essential for the integrity of the genetic blueprint.

Other options do not represent a nitrogenous base that pairs with guanine. Deoxyribose and ribose are sugars that are components of DNA and RNA, respectively, but they are not nitrogenous bases. Thymine, while a nitrogenous base in DNA, pairs with adenine rather than guanine. Thus, the correct pairing with guanine in DNA is indeed cytosine.