The cell nucleus contains the majority of the cell's genetic material in the form of multiple linear DNA molecules organized into structures called chromosomes.Each human cell contains roughly two meters of DNA.he cell nucleus contains the majority of the cell's genetic material in the form of multiple linear DNA molecules organized into structures called chromosomes.
After humans, the nature's relatively largest brain is that of the dolphin: 2 kg. A dolphin weighing 120 kg (280 pounds) has a 1.7 kg (4 pounds) brain; compared to its size, this is almost thrice than a chimp.
The most common types of primary brain tumors among adults are astrocytoma, meningiom (a tumor that arises from the membranes surrounding the brain and spinal cord) and oligodendroglioma. The most common type of primary brain tumors in children are medulloblastoma, grade I or II astrocytoma, (or glioma) ependymoma, and brain stem glioma.