The structure of DNA plays a crucial role in its function as a carrier of genetic information. DNA, or deoxyribonucleic acid, is a long, double-stranded molecule composed of nucleotides, which are the building blocks of DNA. Each nucleotide consists of a sugar molecule deoxyribose , a phosphate group, and one of four nitrogenous bases: adenine A , cytosine C , guanine G , and thymine T . The DNA structure can be described in terms of three key features: the double helix, complementary base pairing, and the antiparallel arrangement of the strands.1. Double helix: The DNA molecule is shaped like a twisted ladder, with the sugar and phosphate groups forming the backbone of the ladder, and the nitrogenous bases forming the rungs. This double helical structure, discovered by James Watson and Francis Crick in 1953, allows DNA to be compact and stable, enabling it to store vast amounts of genetic information within the small confines of a cell's nucleus.2. Complementary base pairing: The nitrogenous bases in DNA pair up in a specific manner, with adenine A always pairing with thymine T , and cytosine C always pairing with guanine G . This is known as complementary base pairing and is a result of hydrogen bonding between the bases. This feature is crucial for DNA replication, as it ensures that the genetic information is accurately copied and passed on to the next generation of cells. When the DNA strands separate during replication, each strand serves as a template for the synthesis of a new complementary strand, ensuring that the genetic information is preserved.3. Antiparallel arrangement: The two strands of DNA run in opposite directions, with one strand running from the 5' to 3' end and the other running from the 3' to 5' end. This antiparallel arrangement is important for DNA replication and transcription, as it allows the enzymes involved in these processes to recognize and bind to specific sequences on the DNA strands.In summary, the structure of DNA is essential for its function as a carrier of genetic information. The double helix provides stability and compactness, while the complementary base pairing and antiparallel arrangement of the strands ensure accurate replication and transcription of the genetic information. These features collectively enable DNA to store, transmit, and express the genetic information necessary for the growth, development, and reproduction of living organisms.