Final answer:
Dehiscence is not the softening of tissue but rather the natural splitting open of a plant structure to release seeds or spores, so the statement is false.
Step-by-step explanation:
The statement 'Dehiscence is the softening of tissue due to excessive moisture' is false. Dehiscence actually refers to the splitting open at maturity of a plant structure, such as a fruit, anther, or sporangium, to release its contents. This process is a natural part of a plant's life cycle and is a means of dispersing seeds or spores.
When dehiscence occurs in fruits, it can allow seeds to be scattered from the parent plant and therefore can increase the chances of survival and propagation of the species. In contrast, tissue softening due to excessive moisture is more accurately described as maceration. Maceration leads to the breakdown of cell walls and the structure of the tissue, resulting in a softer texture.