Plant Tropisms and Mammalian Response Systems
This page continues the discussion on plant tropisms, focusing on root responses and providing evidence for tropism mechanisms.
Example: Positive geotropism in roots occurs when IAA redistributes to the side facing gravity, causing slower growth on that side and bending the root towards gravity.
The page lists several pieces of evidence supporting the role of IAA in tropisms, such as the effects of removing the shoot tip or using chemicals to block IAA movement.
The second half of the page introduces mammalian response systems, highlighting the roles of the nervous and hormonal systems.
Definition: The nervous system coordinates fast, short-acting, and localized responses to stimuli.
The pathway of the nervous system is outlined, from stimulus detection to response execution.
Highlight: Receptors act as transducers, converting stimulus energy into nerve impulses.
Two examples of receptors are introduced: the Pacinian corpuscle and the retina of the eye.