Lesson 6 of 15
Where a plant grows
Show on a big screenCut the tip off an onion root. The root stops growing longer.
Loading lab…
Step 1 of 4
- A plant has a stem, leaves, and roots.
- The shoot tip can still divide.
- A bud partway up the stem can too.
- The root tip, underground, can also divide.
Rule
Meristem is plant tissue whose cells keep dividing. Apical meristem lengthens. Lateral meristem widens. Intercalary meristem lets grass regrow after cutting.
A node is a point on a stem where a leaf grows.
- Apical meristem — at the tips of roots and shoots.
- Lateral meristem — a ring inside the stem.
- Intercalary meristem — near the nodes of some plants, like grass.
The tip of a root holds apical meristem. Cut it off and the root cannot grow longer.
Meristem cells are small. They have thin walls and a large nucleus. Their cytoplasm, the jelly-like fill inside a cell, is dense.
Some new cells stop dividing and start a job. This is differentiation. They become permanent tissue. Permanent tissue is made of cells that have stopped dividing.
Try the lab to finish this lesson.