Intellectual or developmental disabilities: Types list. The list of types of Intellectual or developmental disabilities mentioned in various sources includes: 1  Cornea Plana 1. 2  Pervasive developmental disorders. 3  Autism. 4  Asperger syndrome. 5  Autism, susceptibility to, 13. 6  Autism, susceptibility to, 10. 7  Autism, susceptibility to, 11.
Definition of MERISTEM. : a formative plant tissue usually made up of small cells capable of dividing indefinitely and giving rise to similar cells or to cells that differentiate to produce the definitive tissues and organs. â merÂ·iÂ·steÂ·matÂ·ic \Ëmer-És-tÉ-Ëma-tik\ adjective.
Apical meristems are the completely undifferentiated (indeterminate) meristems in a plant. These differentiate into three kinds of primary meristems. The primary meristems in turn produce the two secondary meristem types.These secondary meristems are also known as lateral meristems because they are involved in lateral growth. At the meristem summit, there is a small group of slowly dividing cells, which is commonly called the central zone.Cells of this zone have a stem cell function and are essential for meristem maintenance.hese secondary meristems are also known as lateral meristems because they are involved in lateral growth. At the meristem summit, there is a small group of slowly dividing cells, which is commonly called the central zone.