When cells having a diploid chromosomal number of 4 normally divide, two cells are formed with 4 chromosomes each. When this division occurs after the application of colchicine, abnormal results are seen.
For a cell of 2n = 4:
Normal cell division – 2 diploid cells with 4 chromosomes each
Abnormal cell division – one tetraploid cell with 8 chromosomes
When we consider a cell of 2n = 18:
Normal cell division – 2 diploid cells with 18 chromosomes each
Abnormal cell division – one tetraploid cell with 36 chromosomes