kerato- or kerat- also cerato- or cerat- pref. 1. Horn; horny: keratosis. 2. Cornea: keratectomy. [Greek kerÄto-, horn, from keras, kerÄt-; see ker- in Indo-European roots.] kerato- or before a vowel kerat- combining form 1. indicating horn or a horny substance: keratin; keratogenous. 2. (Medicine) indicating the cornea: keratoplasty. [from Greek kerat-, keras horn] kerato- a combining form meaning âcorneaâ: keratoplasty.
Early root growth is one of the functions of the apical meristem located near the tip of the root. The meristem cells more or less continuously divide, producing more meristem, root cap cells (these are sacrificed to protect the meristem), and undifferentiated root cells.
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: