<span>Some amino acids have multiple different codons that can code for them. So for some point mutations, one wrong nucleotide in a codon may still allow it to code for the same amino acid. For example. Serine has 4 different possible codons which can code for it. UCA, UCC, UCU, and UCG. Note that if the last letter were change in any instance, it would still code for serine. There are MANY other examples for this question; almost all amino acids have more than one codon which can code for it.</span>
Plastid is not an organelle of animal cells.