5
$\begingroup$

From my understanding, single celled organisms have been seen avoiding, and chasing, potential food or other organisms.

How do they accomplish this? They do not have eyes or ears or a nervous system. My understanding is that chemical reactions are involved somehow.

How do single-celled predators chase other cells? What happens on a chemical level?

Edit:To help keep a more constrained question, the single-celled organism I am considering is Paramecium

Improve this question
$\endgroup$
6
  • $\begingroup$ This is actually a very broad question. Chemotaxis (the response to changes in a chemical in the environment) is only one of the "taxis". If you could refine this, say by singling out one single celled predator, I think it would be a less broad question. $\endgroup$ – anongoodnurse Aug 10 '15 at 16:00
  • $\begingroup$ @anongoodnurse I am trying to find a common predatory Ciliate that does the behavior that I have described - is Paramecium a good example? $\endgroup$ – DoubleDouble Aug 10 '15 at 16:11
  • $\begingroup$ Yes, paramecium is a good example. $\endgroup$ – anongoodnurse Aug 10 '15 at 16:13
  • 1
    $\begingroup$ it is always useful to show work you've done yourself to answer the question. $\endgroup$ – aaaaa says reinstate Monica Aug 10 '15 at 16:35
  • $\begingroup$ @aaaaaa my work so far is essentially google searches leading to links which fail to answer the question. All I can find is definitions of "single-celled organisms", "paramecium", or broad explanations of the digestive system. $\endgroup$ – DoubleDouble Aug 10 '15 at 17:00
1
$\begingroup$

Detection of and movement according to a gradient of a chemical species is a strategy that single cells use to track a target across space. There are very many strategies of movement depending on the cell and its environment, but a common problem that while cells can sense the concentration of chemicals, they cannot sense its gradient (the direction in which it increases) because they are of too small a size to rely on the difference of concentration on one side and the other. Howard Berg and his co-workers have discovered a mechanism that allows single cells to move toward increasing concentration zones by a combination of concentration sampling and movement. See his webpage, http://www.rowland.harvard.edu/labs/bacteria/projects/track.php

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.