Answer:
Mutation, fertilization, meiosis are different mechanisms by which changes can occur in the genome.
Explanation:
There are several process which is responsible for causing change in the genome of the species which results in the evolution of that species. Some of these processes are:
1. Mutation: In mutation, some nucleotide sequences get change and this change can occur due to frameshift, addition, deletion or any other process. This change in nucleotide can be seen in phenotype and helps in the evolution of the species.
2. Fertilization: During fertilization mixing of the genome of two individual takes place which results in producing a genetically distinct offspring which contains variation. So as the offspring is genetically different it can contain new alleles that can help the individual to survive in the changing environment.