Shipments of live animals, including poultry, reptiles, and bees, have very specific packaging requirements. Although you can drop these animals at any Post Office location, they are only shipped when the right transportation is available. With a few exceptions, pets and warm-blooded animals may not go in the mail.
A series of codons in part of a messenger RNA (mRNA) molecule. Each codon consists of three nucleotides, usually corresponding to a single amino acid. The nucleotides are abbreviated with the letters A, U, G and C. This is mRNA, which uses U (uracil).DNA uses T (thymine) instead.he portion of the genome that codes for a protein or an RNA is called a gene. Those genes that code for proteins are composed of tri-nucleotide units called codons, each coding for a single amino acid. Each nucleotide sub-unit consists of a phosphate, a deoxyribose sugar, and one of the four nitrogenous nucleobases.
In fact, even two nucleotides per amino acid (a doublet code) could not account for 20 amino acids (with four bases and a doublet code, there would only be 16 possible combinations [4 2 = 16]). Thus, the smallest combination of four bases that could encode all 20 amino acids would be a triplet code.However, a triplet code produces 64 (4 3 = 64) possible combinations, or codons. Thus, a triplet code introduces the problem of there being more than three times the number of codons than amino acids.hus, the smallest combination of four bases that could encode all 20 amino acids would be a triplet code. However, a triplet code produces 64 (4 3 = 64) possible combinations, or codons. Thus, a triplet code introduces the problem of there being more than three times the number of codons than amino acids.