Abehavior in which animals move toward or away from a light source.

Phototaxis

Explanation: Phototaxis is the phenomenon by which locomotory movement of the organism occurs towards or away from the stimulus of the light.

This is advantageous for the phototropic organism as they can move efficiently towards the sunlight which helps them to make food by the help of sunlight and other substances.

The phototaxis is called positive if the movement is towards sunlight and negative if the movement is against light.

b. read the phase at the intersection of any given temperature and pressure.