Tree roots. Image credit

Tree roots. Image credit

ZIMSEC O Level Combined Science Notes: Examining the structure of stems and roots

Aim: To examine the structure of roots and stems under a microscope/bio-viewer.

Materials: Bio-set and bio-viewers, microscopes, prepared slides of root and stem sections.


Structure of roots. Image credit

Structure of roots. Image credit

  1. The diagram above shows labelled parts of a root plant as seen under a microscope. See if you can identify these parts on your own slide.


The following structures are either found in the root or stem of plants or both as shown in the table below:

Vascular tissueyesyes
Root hairsyes no
  • Epidermis- is a single-layer of cells that covers the leaves, flowers, roots and stems of plants. It forms a boundary between the plant and the external environment.
  • Exodermis-a layer of the outer living cortical cells of plants that takes over the functions of the epidermis in roots lacking secondary thickening.
  • Xylem- is a continuous system that transports water and dissolved mineral nutrients throughout the plant from the roots.
  • Cortex-is the outermost layer of the stem or root of a plant, formed on the outside by the epidermis and on the inside by the endodermis.
  • Phloem- transports sugars, proteins and minerals around the plant.

To access more topics go to the Combined Science Notes page.

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