Answer:
The statement that best summarizes Gregory Mendel's contribution to science is that Mendel found evidence that there are two factors for each trait.
Explanation:
Mendel is known as the father of genetics. He formulated, through the work he carried out with different varieties of pea, the so-called laws of Mendel that gave rise to genetic inheritance.
By his work he found evidences that there are two factors responsible for carrying the traits from one generation to another. These two forms of traits were dominant (visible in F1 generation) and recessive (visible in F2 generation).
For Example: In peas, the yellow color of the seeds is dominant over the green color, which is recessive.