There are 3 for every codon.
Nucleotide substitutions in a gene occur at a relatively constant rate.
A nonsynonymous substitution is a nucleotide mutation that alters the amino acid sequence of a protein. Nonsynonymous substitutions differ from synonymous substitutions, which do not alter amino acid sequences and are (sometimes) silent mutations.
Homologous chromosomes contain the same genes and the same locations, or loci but may have different alleles. But jsut so this definition makes sense, lets define some of the words.
A gene contains the traits that is passed down from two parents to its offspring. An allele is one part of a pair of genes that are located in a particular spot that controls the same trait.
First:mRNA Second:Cytoplasm
