Biology 2601A/B Lecture Notes - Lecture 9: Suberin, Root Cap, Root Hair
13 Nov 2018
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Document Summary
Roots grow from the tip = where new cell division is taking place. As you go back along the axis of a root, you"re going further and further into older tissue (older as you go up in the root) Root hairs are site of absorption of water, salt and nutrients. Casparian band: modification that gives plants selectivity of what gets into the vascular tissue. Meristematic zone: cells divide both in the direction of the root base to form cells that will differentiate into the tissues of the functional root and in the direction of the root apex to form the root cap. Root cap: protects meristematic cells as the root expands into the soil. Central to perception of gravity, the signal that directs the growth of roots downward = gravitropic response. Elongation zone: cells elongate rapidly and undergo a final round of divisions to produce a central ring of cells = the epidermis.
