So, if the birthrate and the death rate are the same, that means that for every person that gets born, one person dies: so the number of people would stay constant. This means that the growth rate is actually 0%.
Polyploidy is a major force in the evolution of both wild and cultivated plants. ... Some of the most important consequences of polyploidy for plant breeding are the increment in plant organs
This would be probably true if the assumption that all possible genotypic variations would be equally distributed (so we would have 25% HH, 25% hh and 2x 25 Hh). If this distribution would be true and Huntingtons disease really was a single gene dominant trait diesase, then yes, we could expect such a distribution in the population.
