A row of cambium cells cuts off 60 cells in one season…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A row of cambium cells cuts off cells in one season. Of these, are cut off towards the pith and become secondary xylem. The rest are cut off towards the bark and become secondary phloem.
- How many cells are cut off outward?
- How many xylem cells are made for each phloem cell?
- What per cent of the cells became xylem?
Need a reminder? The key ideaShow
Secondary growth makes dicot stems and roots thicker. It is done by the vascular cambium and the cork cambium. A dicot vascular bundle is open, with fascicular cambium between the xylem and the phloem. Interfascicular cambium forms from cells of the medullary rays, and the two join into a ring. The cambium cuts off secondary xylem inward and secondary phloem outward, and makes much more xylem than phloem. Monocot bundles are closed and have no cambium. In a dicot root the cambium arises from conjunctive tissue and the pericycle.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Outward. cells.
Step 2. Ratio. xylem cells for each phloem cell.
Step 3. Share. .
Answer: cells; ; .
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