Question

A diploid cell in a plant undergoes chromosome duplication but fails to divide properly, initiating a tetraploid (4n) branch. This branch produces a 4n flower. What can happen next?
The 4n flower produces 1n (haploid) gametes, which then cross-fertilize with gametes from the original diploid parent species to produce fertile offspring.
The tetraploid (4n) flower produces 2n gametes and may then be able to self-pollinate to produce fertile 4n offspring.
The 4n flower produces 4n (tetraploid) gametes, which then self-fertilize to produce fertile offspring.
The 4n flower produces 2n gametes, which then cross-fertilize with gametes from the original diploid parent species to produce fertile offspring.

Answer 1

The correct answer is: The tetraploid (4n) flower produces 2n gametes and may then be able to self-pollinate to produce fertile 4n offspring.  

Gametes are produced via meiosis, which is reduction cell division, meaning that cell from diploid (2n) becomes with haploid (n) number of chromosomes. In the example above, 4n flower will produce 2n gametes. Ovary of the flower produces ovule-the female gamete which is ready for fertilization. The anther produces pollen that lands on a mature stigma of a flower and grows a pollen tube down into the flower. Pollen then produces male gametes-sperm by mitosis and releases them for fertilization.