Answer:
Natural Selection
Explanation:
In natural selection process of evolution, traits that are essential for an individual to be fit enough to survive under environmental stress become dominant.
Since the flowers are of blue or yellow color, it is essential for a bee to be able enough to perceive the blue and yellow color. Hence, the eyes of bee with time have evolved to perceive these two color so that they can pollinate flower.
The answer is D. Food Threshold is the amount of food capable on feeding the organisms.
The independent variable is the one variable you manipulate in the experiment
The dependent variable (or responding variable) changes as a result of the independent variable
