Heredity and Genetics
Heredity or transmission of genetic characters from parents to the offspring deals with the phenomenon of like begets like, that is, members of each species breed true to their type. Thus maize plants form grains that grow to form Maize plants or cats are produced only by cats. In other words, heredity operates within the confines of a species.
The complete set of genes in an organism’s genome is called genotype.
The observable characters in an organism make the phenotype. Phenotype is a result of genotype’s interaction with the environment. Due to this reason, many phenotypes are not inheritable.
Deoxyribonucleic acid (DNA) is an extremely long macromolecule that is the main component of chromosomes and is the material that transfers genetic characteristics in all life forms, constructed of two nucleotide strands coiled around each other in a ladder like arrangement with the side pieces composed of alternating phosphateand deoxyribose units and the rungs composed of the purine andpyrimidine bases adenine, guanine, cytosine, and thymine. The genetic information of DNA is encoded in the sequence of the bases and is transcribed as the strands unwind and replicate.
RNA stands for ribonucleic acid. It is an important molecule with long chains of nucleotides. A nucleotide contains a nitrogenous base, a ribose sugar, and a phosphate. Just like DNA, RNA is vital for living beings.