How many nucleotides make up a codon?
A gene is a region of a DNA molecule (or RNA in viruses) that encodes a polypeptide (a transport or ribosomal RNA molecule). A genome is a collection of genes contained in a haploid set of cell chromosomes. A single gene represents each gene from an allele. The genome is a collection of hereditary traits. A gene is a region of a DNA molecule (RNA viruses in many) that encodes the primary structure of a polypeptide (transport or ribosomal RNA molecule). A genome is a collection of genes contained in a haploid set of cell chromosomes. The genome is a collection of hereditary characters.
Codon (triplet) is a unit of the genetic code. It consists of 3 consecutive nucleotides. The sequence of codons in the gene determines the sequence of distribution of amino acids in the polypeptide chain of the protein encoded by this gene. Nucleotides (nucleoside phosphates) and phosphoric esters of nucleosides consist of a nitrogenous base (purine or pyrimidine), a carbohydrate (ribose or deoxyribose) and one or more phosphoric acid residues. Compounds from one, two, three, several or many nucleotide residues are respectively named mono-, di-, tri-, oligo- or polynucleotides.
Nucleic acids (polynucleotides) and high-molecular organic compounds are formed by nucleotide residues. The sequence of nucleotides in nucleic acids determines their primary structure. Nucleic acids carry out the most important functions for the storage and transfer of genetic information, participate in the mechanisms of synthesis of cellular proteins. They are in a free state and in combination with proteins (nucleoproteins) in the body. Genetics pave the way for effective management of heredity and the variability of organisms. At the same time, selection relies on the achievements of other sciences: systematics and geography of plants and animals, cytology, embryology, biology of individual development, molecular biology, physiology and biochemistry. The rapid development of these areas of natural science opens up entirely new prospects.
The genetics has already reached the level to be able to make design of organisms with the necessary characteristics and properties. Genetics has a decisive role in solving almost all breeding tasks. It helps rationally (based on the laws of heredity and variability) to plan the selection process taking into account the inheritance characteristics of each specific feature.
The achievements of genetics, the law of homologous series of hereditary variability, the use of tests for the early diagnosis of the selection potential of the material, the development of a variety of methods for experimental mutagenesis and remote hybridization in combination with polyploidization, the search for methods for controlling recombination processes and efficient selection of the most valuable genotypes with the required complex of characteristics and properties gave mankind the opportunity to expand sources of source material for breeding. In addition, the widespread use of methods of biotechnology, cell culture and tissue in recent years have made it possible to significantly accelerate the selection process and put it on a qualitatively new basis.