Tropism

What is Auxin and what is its role in tropism?

Auxin is a plant growth hormone that is responsible for the directional growth in tropism. High Auxin concentration in shoots promote cell elongation and in roots, high concentration of Auxin inhibits cell elongation.

Explain the benefit of tropism

Tropism a growth movement of a plant in response to external stimulus, usually to stimulus that will affect the way the plant photosynthesizes or the rate in which they grow. Tropism is important in plants because it allows them to maximize important resources and minimize stimuli that will potentially harm the plant. For example, a stem tip will grow towards light in order to maximize the amount of light needed for photosynthesis.

Give an example of negative tropism

1)Stem tip will grow against gravity (- geotropism) in order to have a higher chance of finding light or 2) Root tip will grow away from the light source (- phototropism) in order to lower the probability of drying out.

What is the difference between Positive and Negative tropism?

Positive tropism is the growth movement towards an external stimuli and Negative tropism is the growth movement away from the stimuli.