Meristematic tissues on the basis of origin and development:
Introduction:
- Meristematic tissues are those tissues that have the ability to divide indefinitely.
- These tissues can originate from various sources in a plant body.
- The two major types of tissues that are divided based on their origin are Primary meristematic tissues and Secondary meristematic tissues.
Detailed explanation:
Primary meristematic tissue:
- These tissues originate from the meristematic cells of the embryo.
- They develop the plant body in its initial growth stages.
- These tissues are responsible for the formation of the primary plant body.
- These meristematic zones persist in the plant throughout its life.
- The primary meristem is located in the apex of root and shoot.
- Primary meristem is the contributing factor to primary growth.
- Primary meristem is of 2 types: Apical meristem and Intercalary meristem.
Secondary meristematic tissues:
- Secondary meristematic tissues is a type of meristem that is involved in the secondary growth and thus gives rise to the secondary tissues of the plant
- These tissues originate from permanent cells that gain the function of division by redifferentiation.
- This meristem is mainly found within the mature roots and shoots.
- These meristems are formed in the later part of a plant's life.
- They are mostly laterally positioned.
- The lateral meristem is an example of a secondary meristem (e.g. cork cambium).
- They are responsible for the increase in girth or width of stems and roots.
- Secondary growth is because of the secondary meristem. These produce the secondary tissues in stems and roots that either replace the primary tissues or add to the overall mass.
FAQ:
1. What are the examples of secondary meristems?
Ans- Secondary meristems are formed later in the life of a plant. These are present in the mature roots and stem regions.
Examples of secondary meristems are:
I. Cambium of root
II. Cork cambium of root
III. Cork cambium of stem
IV. Interfascicular cambium and fascicular cambium of stem