DNA is characterized by which of the following features? DNA is best characterized as a double-stranded, antiparallel double helix made of nucleotides. Still, each nucleotide contains deoxyribose sugar, a phosphate group, and one of four nitrogenous bases: adenine (A), thymine (T), guanine (G), or cytosine (C). Complementary base pairing—A with T and G with C—allows DNA to store genetic information, replicate accurately, and direct the production of proteins Surprisingly effective..
This changes depending on context. Keep that in mind.
Introduction: DNA at a Glance
Deoxyribonucleic acid, or DNA, is the hereditary molecule found in nearly all living organisms and many viruses. Still, it carries the instructions needed to build, maintain, and reproduce an organism. These instructions are encoded in the order of its bases, much as letters form words in a sentence It's one of those things that adds up..
A typical biology question about DNA usually seeks one or more of these defining features:
- Two polynucleotide strands arranged as a double helix
- Deoxyribose rather than ribose sugar
- A sugar-phosphate backbone
- The bases adenine, thymine, guanine, and cytosine
- Complementary base pairing between A–T and G–C
- Two strands running in opposite, or antiparallel, directions
- The ability to be copied through semiconservative replication
Not every DNA molecule has every large-scale property. As an example, some viral DNA is single-stranded, while cellular DNA may be linear or circular. Still, the features above describe the canonical DNA structure found in cells.
The Basic Building Blocks of DNA
DNA is a polymer, meaning that it consists of many repeating units joined together. Its repeating units are called nucleotides. Every DNA nucleotide has three parts:
- Deoxyribose sugar — a five-carbon sugar that gives DNA its name.
- Phosphate group — connects sugars to form the structural backbone.
- Nitrogenous base — carries the information encoded in DNA.
The four standard DNA bases belong to two chemical groups. Which means Adenine and guanine are purines, which have a double-ring structure. Cytosine and thymine are pyrimidines, which have a single-ring structure.
