DNA and Genetic Coding

DNA stands for deoxyribonucleic acid and it is the genetic material that carries the instructions for the development, functioning, and reproduction of all living organisms. DNA is double-stranded and made up of nucleotides, which consist of a phosphate group, a deoxyribose sugar molecule, and a nitrogenous base (adenine, thymine, cytosine, or guanine). The two strands of DNA are held together by hydrogen bonds between the complementary bases.

A gene is a section of DNA that contains the instructions for producing a specific protein. Each unique gene has a unique sequence of bases, and this sequence determines the order of amino acids in the protein. Genes are responsible for various traits and characteristics of an organism.

Proteins play a crucial role in determining an organism's phenotype, which refers to its observable traits and characteristics. Proteins are formed based on the sequence of bases in the DNA, and different proteins, as well as combinations of them, contribute to the development and functioning of various bodily structures and processes. Therefore, the unique set of proteins produced from DNA sequences ultimately determines an organism's phenotype.

The four nitrogenous bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). These bases pair up with each other in a complementary manner, with adenine always pairing with thymine and cytosine always pairing with guanine.

Complementarity in DNA refers to the specific base pairing between adenine and thymine, and cytosine and guanine. Adenine forms hydrogen bonds with thymine, and cytosine forms hydrogen bonds with guanine. This complementary base pairing allows the two strands of DNA to bind together and maintain the overall structure of the DNA molecule.