Another frequent reason for lack of successful fertilization is chromosomal imbalance. For example, the common banana is triploid. In other words, it has three sets of chromosomes. Instead of having one set of chromosomes from each parent, it has two sets from one parent and one set from the other parent. Triploids seldom produce eggs or sperm that have a balanced set of chromosomes and so successful seed set is very rare. Bananas, too, are parthenocarpic and produce fruit in the absence of successful fertilization. These bananas are asexually propagated. After the stalk has flowered and borne fruit, it dies. But there are side shoots or suckers at the base of the main stalk, which can be removed and replanted to continue the cultivar. Growers also propagate bananas by tissue culture.