What would be the ploidy of the viable gametes produced by a tetraploid individual if nondisjunction of all chromosomes occurred in meiosis i?

Tetraploid

Explanation:

Ploidy:

Ploidy is a biological term used for the presence of number of chromosome sets in a cell. Cells can be haploid (gametes), diploid (two chromosomal sets) and polyploid (more than two chromosomal sets).

Polyploidy:

A condition that entails the possession of more than two sets of chromosomes in the cell. Normal cells are diploid (2n) i. e they contain two sets of chromosomes, one from each parents. Polyploid individuals contain three (triploid, 3n), four (tetraploid, 4n), five (pentaploid, 5n) number of chromosomes and so on.

Under normal disjunction of chromosomes, a tetraploid cell will produce two diploid daughter cells each with two sets of chromosomes.

However, in the case of non-disjunction of all chromosomes in a tetraploid individual, two tetraploid daughter cells will be produced at the end of meiosis 1.

Non-disjunction of all chromosomes means that one daughter cell has received all 4 sets of chromosomes while the other is null i. e. contains zero chromosomal sets.