Final answer:
The irregularities on the surface of a freeze-fractured specimen can be caused by the deviation of cell structures, localized melting of the ice, and sublimation of the ice.
Step-by-step explanation:
When a freeze-fractured specimen is examined, irregularities can be observed on its surface. These irregularities are caused by various factors. One of the main factors is the deviation of cell structures. The fractures may deviate the fracture plane upward or downward, resulting in irregularities on the surface of the specimen. Another factor is localized melting of the ice. The heat generated during the freezing process can cause localized melting, which leads to the formation of irregularities. Lastly, sublimation of the ice can also cause irregularities on the surface of the freeze-fractured specimen. As the ice sublimes, it can create uneven surfaces and cause irregularities.