Final answer:
Genetic information is coded by the sequence of nucleotides in DNA, which is transcribed into mRNA and translated into proteins, following the central dogma. This process involves ribosomes and dictates the genotype and phenotype of an organism.
Step-by-step explanation:
Genetic information in a cell is coded by the sequence of nucleotides in DNA. DNA consists of four nitrogenous bases (adenine, thymine, cytosine, and guanine in DNA; uracil replaces thymine in RNA). These bases pair up in sequences to form the genetic code. In the process known as transcription, a segment of DNA is copied into messenger RNA (mRNA), which is then used as a template during translation to assemble proteins. This sequence of events is part of the central dogma of molecular biology. Proteins are synthesized on ribosomes in the cell, with the mRNA dictating the order in which amino acids are added to the growing polypeptide chain, according to the three-base codons that correspond to specific amino acids.
The genetic code is universal, meaning that a codon specifies the same amino acid in all organisms. This genetic code is what dictates the genotype of an organism and is translated into physical traits, or phenotype.