The large size and exceptional vigor of certain varieties of wheat, apples, and zinnias are due to the possession of extra sets of chromosomes, which result from:
1. Polyploidy: This is the condition where an organism has more than two complete sets of chromosomes. In the case of wheat, apples, and zinnias, the presence of extra sets of chromosomes leads to increased genetic material, which can contribute to enhanced growth, size, and vigor. This phenomenon is a result of the nondisjunction of complete sets of chromosomes during cell division.
2. Example: In wheat, there are varieties like hexaploid wheat that have six sets of chromosomes instead of the usual two sets. This polyploidy contributes to the larger grain size and better yields in these wheat varieties compared to diploid wheat.
By having these extra sets of chromosomes, these plants can exhibit characteristics like increased size, better disease resistance, and improved yield, making them valuable in agriculture and horticulture.
