From dividing to doing a job
Differentiation turns meristem cells into permanent tissue.
Not every new cell keeps dividing
A root tip keeps making new cells. But the older part of the root does other jobs: it holds the plant, carries water and stores food.
What must happen to some of the new cells?
What this lesson covers
The idea
Some new cells from meristems stay meristematic, while others lose the ability to divide and change in structure and function to become specialised permanent tissue; this process is called differentiation.
Not every new cell keeps dividing
A root tip keeps making new cells. But the older part of the root does other jobs: it holds the plant, carries water and stores food.
What must happen to some of the new cells?
- They stop dividing and change to do a special job
- They all keep dividing forever
- They disappear
Cells left behind
Let the tip cells divide a few times. Then let the older cells specialise.
Differentiation
Because of continuous cell division, a meristematic tissue adds new cells to the plant body. Some of the new cells remain meristematic. Others lose the ability to divide and change in structure and function. They become permanent tissues, specialised for jobs such as support, transport or storage. This process is called differentiation.
Notes
New cells from meristems either stay meristematic or lose the ability to divide and become permanent tissue for support, transport or storage. This change is differentiation.
Check yourself
Meristematic tissue becomes permanent tissue by the process of…
What happens to some of the new cells made by a meristem?
A meristem makes 12 new cells. 4 of them stay meristematic and the rest lose the ability to divide. How many become permanent cells?
Answer: 8 cells
12 − 4 = 8 cells become permanent tissue.
Which job can a permanent tissue cell do?
- differentiation — correct. Yes.
- transpiration. That is loss of water vapour through stomata.
- photosynthesis. That is how plants make food.
- They all stay meristematic for ever. Some remain meristematic, others do not.
- They lose the ability to divide and become specialised — correct. Yes. They become permanent tissue.
- They become animal cells. Plant cells stay plant cells.
- Support, transport or storage — correct. Yes.
- Divide all the time to add new cells. That is the job of meristematic cells.
- Make the plant grow longer at the tip. That is done by the apical meristem.