Functions of the kidneys. 1  Filter and remove excess fluid, waste and toxic substances from the blood as urine. 2  Regulate the chemical composition of blood such as salt, potassium and acid. 3  Secrete three important hormones: 4  Erythropoietin: hormone which is needed to stimulate the production of red blood cells.
These cells include skin cells, blood cells, and any cell other than sex cells. Meiosis is the process that creates sex cells. These cells include sperm and egg cells. Seminiferous tubules are structures located in the male reproductive gland known as the testis. Meiosis in males occurs in the seminiferous tubules. This means that the seminiferous tubules are crucial in the process of reproduction. The seminiferous tubules consist of a network of tubes that are lined with a type of cell known as a sertoli cells. Sertoli cells are long columnar cells that are differentiated during the process of meiosis to form sperm.
Manganese nodule. Polymetallic nodules, also called manganese nodules, are rock concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. The core may be microscopically small and is sometimes completely transformed into manganese minerals by crystallization.