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Lesson: Chapter 1 — Living Tissues

1.1.2. Permanent tissue 1 of 3

What permanent means

Everything in a plant that is not still dividing is permanent tissue — which is almost all of it.

Activity 1.3

  • You need the stem of a plant such as pumpkin or Tridax, a glass slide and a microscope.
  • Observe a thin cross-section of the stem under the microscope.
  • Identify the kinds of tissue present in it.

Figure to be added

Figure 1.5 — a cross-section of a dicotyledonous stem under the microscope, with one wedge of it enlarged to show the different tissues: a ring of darker thick-walled cells near the outside and large pale thin-walled cells filling the centre.

Permanent tissue

Tissue that cannot divide further and has become specialised to carry out a definite function is called permanent tissue.

Two groups, by how many kinds of cell

Permanent tissues are divided in two according to their nature:

  • Simple permanent tissue — cells of only one kind are grouped together.
  • Complex permanent tissue — several kinds of cell are grouped together.

Beyond the syllabus — how permanent is permanent?

Parenchyma keeps the ability to divide even after it has specialised. That is what makes a plant able to heal a wound, and it is where the cork cambium and part of the ring cambium come from. For this chapter take permanent to mean a cell has stopped dividing and taken up a job — which is what the classification is about — rather than that it could never divide again.