Final answer:
DNA has a structure known as a double helix, composed of two strands of nucleotides bonded via hydrogen bonds, resembling a spiral staircase with a very stable form ideal for storing genetic information.
Step-by-step explanation:
Nucleotides are arranged in two long strands that form a spiral called a double helix.
DNA, or deoxyribonucleic acid, is composed of two long strands of nucleotides. These strands bond with each other through hydrogen bonds between their nitrogenous bases, forming the iconic structure known as a double helix. Each nucleotide consists of a nitrogenous base, a five-carbon sugar (deoxyribose), and a phosphate group. These elements form a backbone of alternating sugar and phosphate portions, with the nitrogenous bases—adenine pairing with thymine, and guanine with cytosine—protruding inside, resembling the steps of a spiral staircase.
The two strands are anti-parallel, meaning they run in opposite directions; one strand runs from a 5' to 3' direction, and the other from 3' to 5'. This specific orientation is crucial for various DNA functions, such as replication and the interactions involved in protein synthesis. Due to its shape and bonding, the double helix is a very stable structure, making it ideal to store and protect the genetic information encoded within the sequence of bases.