Final answer:
Hyperplasia is an increase in the number of cells, often causing tissue enlargement, while hypoplasia involves underdevelopment due to fewer cells. In plants, hyperplasia, abnormal growth patterns, and discoloration can indicate viral diseases. Understanding these terms helps diagnose different conditions.
Step-by-step explanation:
Hyperplasia and hypoplasia are terms used to describe changes in cell growth and development. Hyperplasia is characterized by an increase in the number of cells, often as a result of cell proliferation in response to a stimulus. This can lead to an enlargement of tissues or organs. In contrast, hypoplasia refers to underdevelopment or incomplete development of a tissue or organ due to a deficiency in cell number. It is important to distinguish these conditions as they can indicate different types of pathological or physiological processes.
In the case of plant diseases, symptoms such as abnormal growth patterns, malformed stems, leaves, or fruit, and discoloration can often be observed. These alterations could signify the presence of diseases or environmental stress affecting the plants. For example, cell necrosis, which refers to the death of cells, can also be a symptom associated with disease or damage.
Given an image such as Figure 21.13, where the micrograph shows the cells of a plant root, one can identify different symptoms. If the cells are enlarged and there is an increase in the number of cells, this would indicate hyperplasia. If instead, there is discoloration and a clear alteration in the structure of the cells, those are also hallmarks of viral disease in plants.