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Growth and Development (Plant)
Posted by : Yoga
Rabu, 26 September 2012
GROWTH and DEVELOPMENT
" Growth is the process of size increase which is can't back to the origin "
- Characteristic of growth :
- It has quantitative property
- It found in meristem tissue (plant)
- The reproduction by mitosis
" Development is process of becoming mature "
- Characteristic of development :
- It has qualitative property
- It found in gamete
- The reproduction by meiosis
- Factors that influence Growth and Development :
- Internal Factors
- External Factors
* Internal Factors are factors that come from inside of the body of the origisms theirself:
- Gene - doesn't appear from outside
- formed of some nucleate acid that is comkposed in macromolecule called DNA
- function as carrier of genetic factors
- Hormone :
- Growth Hormone : Race growth
- The hormone of growth inhibitor : To stop the activity of growth & development
- The hormone of body organs former : To stimulate the formation of body organs
- Injury hormone : that stimulates formation of new tissue
* External Factors are factors that come from outside of the body of the organisms their self:
- Food is main factor for growth & development of the organisms
- Temperature
- Light (Ray)
- Air humidity
The growth & development of plants :
* Growth in plants
- Happens in meristematic region, in tip of stem & the tip of root.
- Kinds of growth in plant :
A) Primary growth is the increment of lenght size in the plants stem because of the activity of primary
meristmatic tissues :
- Cell fision region = Happens multiplication of cells
- Cell extension region = Happens the change of cells size
- Cell differenciation region = Happens the development of cells
B) Secondary growth is the increment of size or thickness of a plant body organs because of the
activity of secondary meristematic tissue.
- Two teories of growth piont in plant :
- Histogenic theory : - Dermatagen
- Periblem
- Pleuron
- Tunica carpus theory : - Tunica
- Corpus
* Development in plant
- Process to reach adultness of that plant. it's qualitative property (can't be measured). Stated by the change of shape & adultness level.
- Plant adult if has formed flower