Portion of the meninges protrudes through the spinal canal wall is? ?

Meningocele

Meningocele (MM) is known as meningeal cyst and it is the protrusion of the membrane that cover the part of spinal cord through the defect in the vertebral column. Thus, Meningocele (MM) is the least common fom of spinal bifida and spina bifida is the bony defect in the vertebral column through the meningeal membrane.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.