The answer to this question would be: alopecia areata
In this question, there is a certain area of the scalp that didn't have any hair. The best term to this condition would be alopecia areata.
There are a few reasons why a spot of baldness can appear. It can be caused by stress that inducing autoimmune disease. Before diagnosing a patient with this you must exclude the possibility of fungal infection as it can destroy the hair and make it look bald.
The correct answer is phosphorylation. When an ADP (Adenine Diphosphate) molecule gains a phosphate, it becomes an (Adenine Triphosphate) molecule. This process is called a phosphorylation. Phosphorylation and its counterpart dephosphorylation change many proteins in terms of its functions and activities.
Oak tree is an example of a biotic factor