Tetraploidy will occur.
Step-by-step explanation:
The process of sexual reproduction is very necessary to maintain the genetic setup of the species over the races.
The normal chromosome content of a cell is called diploid state of cell. Its represented by the expression 2n. The cell division that takes place before the gamete formation is called meiosis. This cell division makes the chromosome number of the cells halved. So haploid cells are produced. Its represented by n.
Now as the gametes fuse, both the n becomes 2n and diploid state is regained.
But if the meiosis don't occur in the gametes, the gametes will remain 2n. So after fertilization, it becomes 4n. This state is called tetraploidy.