They must occur in the DNA, which is in each cells nucleus. More specifically the nucleolus of the cell. A mutation occurs in an allele, where a base triplet (or a codon) gets transcribed incorrectly.
1 diploid cell (2n) cell becomes 4 haploid (n) germ cells (eggs or sperm). During meiosis, chromosomes are replicated once in S phase (just like mitosis), but the cell divides twice. ... The result: chromosomes after meiosis are genetically unique and have combinations of DNA derived from both parents.
A community which is a ecosystem
