plant cells?

Question

many plant cells have more than two complete sets of chromosomes in each cell. Why and how might this occur?

Answer 1

That answers what polyploid plants are, but not how they happen. Basically polyploid plants are the result of a mistake during meiosis. Instead of normal separation of chromosomes (1/2 to each new cell) all of the chromosome pairs go to one side and none to the other. You end up with a 2N gamete. For some reason in plants this is much more acceptable.

So, if you fertilize a 2N egg with a 1N pollen you get a 3N plant (such as banana), or if you fertilize a 2N egg with a 2N pollen you get a 4N plant, etc....

Answer 2

Plants that having more than two homologous chromosomal sets are called polyploid plants.

Many crop plants are polyploid, because polyploid plants are usually more robust, and robust plants are usually selected in selective breeding and propagation. Therefore the polyploidy is propagated.

You’d be interested to know that most banana varieties are triploid (3 sets homologous chromosomes) of and most potatoes are tetraploid. (4 sets homologous chromosomes).