I think its becasue Females have 2 X chromosomes to choose frm and males only have one x chromosome so its automatically dominant to the Y
The plant is responding to pigments.
The answer would be hypothalamus.
Hypothalamus is a part of the brain that located below the thalamus (hypo mean "under"). Hypothalamus can control nervous and endocrine system. It was divided into front/anterior, tuberal and back/posterior part. Thirst would be regulated by anterior and posterior part, temperature by anterior part and sexual behaviour by anterior part.