Sertoli cell, Sertoli's cell-elongated cells found in the seminiferous tubules of the testis; apparently they nourish the spermatids. biological science, biology-the science that studies living organisms. plant cell-a cell that is a structural and functional unit of a plant.
The life expectancy of a toilet is more than 100 years. In fact, a study conducted by the National Association of Home Builders determined that toilets can last indefinitely.
Most research on toilet training is descriptive, although some is evidence based. In the United States, the average age at which training begins has increased over the past four decades from earlier than 18 months of age to between 21 and 36 months of age.