Ageing is the process where there is a continuous decline in the metabolism of the body. The hearing power also declines after the age of 40 years. Presbycusis is the term which is generally used for hearing impairment due to old age. It is mainly caused due to degeneration of the cochlea or associated structures of the inner ear or auditory nerves.

Maleic hydrazide : It is a growth retardant which checks cell division. So during seed storage this is applied for checking sprouting of potato tubers so that the importance of potato may not be lowered down.

All epithelia are separated from their underlying tissues by an extracellular basement membrane which is fibrous in nature. The basement membrane is the fusion of two lamina namely, the basal lamina and the reticular lamina. The lamina reticularis is attached to the basal lamina with collagen anchoring fibrils and fibrillin microfibrils. The two layers together are collectively referred to as the basement membrane.

Division of the nucleus is called karyokinesis. The process of partition of a cell's nucleus into the daughter cells during cell division is called karyokinesis. All the changes in a nucleus that occur during cell division are collectively termed as karyokinesis. It has four stages prophase, metaphase, anaphase, and telophase.

All nuclear changes (Prophase, metaphase, anaphase, and telophase) that occurs during mitotic cell division are collectively called as karyokinesis. Mitotic cell division consists of two steps. The first step is karyokinesis where nuclear division takes place which is followed by cytokinesis i.e the division of cytoplasm takes place and individual daughter cells are formed. So, the correct answer is 'Karyokinesis'.