How is DNA structured?

How is DNA structured?

• A. Single-stranded helix made of nucleotides
• B. Double helix made of nucleotides
• C. Triple helix of proteins
• D. Linear sequence of amino acids

Answer: (B)

The structure of DNA is best described as a double helix made of nucleotides. This means that DNA consists of two long strands that wind around each other, resembling a twisted ladder. Each strand is composed of a sequence of nucleotides, which are the building blocks of DNA. Nucleotides are made up of three components: a phosphate group, a sugar (deoxyribose in DNA), and a nitrogenous base (adenine, thymine, cytosine, or guanine). The two strands of the DNA helix are held together by hydrogen bonds between complementary pairs of nitrogenous bases: adenine pairs with thymine, and cytosine pairs with guanine. This specific pairing stabilizes the double helical structure and allows for the accurate replication of DNA during cell division. In contrast, the other choices describe structures that do not accurately represent DNA. A single-stranded helix would not provide the stability and complementary base pairing found in DNA. A triple helix of proteins does not describe DNA, as DNA is not structured that way; rather, proteins can be composed of amino acids but are separate from DNA. Lastly, a linear sequence of amino acids refers to the structure of proteins, not DNA,

The structure of DNA is best described as a double helix made of nucleotides. This means that DNA consists of two long strands that wind around each other, resembling a twisted ladder. Each strand is composed of a sequence of nucleotides, which are the building blocks of DNA. Nucleotides are made up of three components: a phosphate group, a sugar (deoxyribose in DNA), and a nitrogenous base (adenine, thymine, cytosine, or guanine).

The two strands of the DNA helix are held together by hydrogen bonds between complementary pairs of nitrogenous bases: adenine pairs with thymine, and cytosine pairs with guanine. This specific pairing stabilizes the double helical structure and allows for the accurate replication of DNA during cell division.

In contrast, the other choices describe structures that do not accurately represent DNA. A single-stranded helix would not provide the stability and complementary base pairing found in DNA. A triple helix of proteins does not describe DNA, as DNA is not structured that way; rather, proteins can be composed of amino acids but are separate from DNA. Lastly, a linear sequence of amino acids refers to the structure of proteins, not DNA,