If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have D. 63 chromosomes in 21 sets of 3 .
Triploidy is considered as the presence of an additional set of chromosomes in the cell for example a total of 69 chromosomes than the normal 46 chromosomes per cell. This extra set of chromosomes arise either from the father or the mother during fertilization.
In general when mitosis is complete, the resulting cell gets two groups of 46 chromosomes, each enclosed with their own nuclear membrane. The cell then divides in two by a process called cytokinesis, That create two clones of the original cell, each with 46 monovalent chromosomes.
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