Abacterial cell is in a solution with a chemical gradient. the bacterial cell directs its movements in order to move toward the highest concentration of glucose molecules within the solution. this is an example of positive

positive chemotaxis

Explanation:Chemotaxis is the movement of an organism in response to a chemical stimuli in it's environment.this response is vital for animals to flee from harm and to locate useful resources. bacteria for example and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment such as glucose by swimming toward the it highest concentration of glucose which is food for it. In this case it is positive chemotaxis because the bacteria moves towards the chemical stimuli .

It may be negative if the bacteria moves away from the chemical stimuli

the dark variety, as they are not visible on the dark tree barks

explanation: