- Phototaxis in photosynthetic living beings
- Phototaxis in insects and other living things
- The impact of phototaxy on human life
- References
The phototaxis or phototaxis reaction is cellular organisms to light stimuli. It can be of two types, depending on the body's reaction to light: positive, when it is close to it; negative, when he moves away from her.
An example of positive phototaxis or phototaxis is that of mosquitoes, flies, or moths. Especially in summer, when their presence is greater, they tend to look for natural or artificial light - light bulbs, for example - and fly around them.
Phototaxism is related to the reaction of cells to light stimuli
On the contrary, other insects such as cockroaches flee from the light, being an example of negative phototaxis.
Phototaxis in photosynthetic living beings
Phototaxism or phototaxis also affects plants. They need light to carry out photosynthesis, the process necessary for their development.
Therefore, they tend to grow seeking greater exposure to sunlight. The leaves of the plants carry out this movement, while the roots always grow against the sunlight.
These directional and growth movements caused by sunlight have a certain internal complexity.
Science studies and explains them as part of the vital processes of plants. Thus, plants receive sunlight through blue wavelength receptors - known as phototropin 1 and 2 -.
There the phosphorylation of proteins occurs, which will trigger the subsequent growth and movement of the plants towards the light.
Phototaxis in insects and other living things
As we explained before, not all insects seek light; some flee from it - negative phototaxis.
In the first case, they are living beings used to using natural light - from the Moon and the stars, for example - to orient themselves.
When they perceive an artificial light source - a spotlight, a light bulb, etc. - tend to approach her. The most obvious example is the mosquitoes that hover around home lamps when the rest of the room is dark.
On the contrary, lucifugal insects are those that flee from light. For example, cockroaches.
These living beings react against light stimuli as they are not typical of their habitats and consider them a threat to their survival.
The impact of phototaxy on human life
Knowing the phenomenon of phototaxism or phototaxis is useful for humans. In the case, for example, of fishing, the reaction of fish to luminous presences - they tend to approach the light and swim towards it - is used by fishermen.
Thus, the use of artificial light is a support technique to increase the volume of the catches. On the other hand, when it comes to insects, the use of special lights can reduce the presence of insects around them.
Thus, it is possible to reduce the presence of mosquitoes during summer nights and avoid bites. In the case of cockroaches, light can be helpful in keeping them away. As we saw, they escape from the light - negative phototaxis - by feeling threatened by it.
References
- Phototaxism. Department of Plant Biology, Carnegie Science carnegiescience.edu.
- Judith P. Armitage & Klaas J. Hellingwerf, 'Light-induced behavioral responses (' phototaxis ') in prokaryotes'. (2003). Kluwer Academic Publishers, Netherlands.
- Why are bugs attracted to light ?, iflscience.com.
- 'Plant Responses to Light: Phototaxis, Photomorphogenesis, and Photoperiodism'. Botany online 1996-2004 at biologie.uni-hamburg.de.
'Photophysiology: General Principles; Action of Light on Plants'. Edited by Arthur C. Giese. (1964). Academic Press New York & London.