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.
On the basis of origin and development of initiating cells, meristems can be divided into three types: (i) Promeristem or priordial meristem: A group of young meristematic cells of a growing organ. It is the early embryonic meristem from which other advanced meristems are derived. In a plant, it occupies a small area at the tip of stem and root. It further divides to form primary meristem. (ii) Primary meristem: These are derived from promeristem. They are present below the promeristem at shoot and root apices. These cells divide and form permanent tissues. (iii) Secondary meristem: