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.
Mammals are the champions. 1. The largest brain belongs to the sperm whale: 7 kg (17.5 pounds). The blue whale, the largest animal on the planet, being twice longer and thrice heavier, has a brain weighing 5 kg (12.5 pounds). 2. Human brain has an average weight of 2.7 pounds (1.2 kg), variations between 1.1 and 1.4 kg being considered normal.
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.