How do seed cells know the difference between top and bottom?
koning at ECSUC.CTSTATEU.EDU
Mon Apr 21 13:36:27 EST 1997
At 1:03 PM -0400 4/21/97, Nanda Somarajan wrote:
> Tropism is just tendency of any organism towards something.
>There are other tropism, including towards light and certain chemicals.
>Many single celled animals that produce their own energy by
>photosynthesis does both light and chemical tropisms.
Rather than "trop-" (bending), in this last case
we usually use "tach-" as in phototaxis or chemotaxis
to indicate the fast locomotion rather than shape
distortion. So moss sperm are called chemotactic
as they swim up a concentration gradient of chemicals
to arrive at the egg.
Ross Koning | koning at ecsu.ctstateu.edu
Biology Department | http://koning.ecsu.ctstateu.edu/
Eastern CT State University | phone: 860-465-5327
Willimantic, CT 06226 USA | fax: 860-465-4479
More information about the Plant-ed