Question

what was thomas hunt morgans main contribution to science?
○ he discovered that certain traits were linked to the x chromosome.
○ he was the first to use fruit flies in research.
○ he created the first white - eyed female drosophila.
○ he created the first white - eyed male drosophila.

Explanation:

Thomas Hunt Morgan's main scientific contribution was discovering that certain traits (like eye color in fruit flies) were linked to the X chromosome, establishing the chromosome theory of inheritance. The other options: using fruit flies was a method, creating white - eyed flies (male or female) were parts of his experiments, not his main contribution.

Answer:

A. He discovered that certain traits were linked to the X chromosome.