If a college math professor only calls on the men in the class, he may be guilty of misogynism, or a hatred of or prejudice against women.
Another word for misogynism is the noun misogyny. Either way, it refers to a dislike for women or a general bias against them. A man or a woman can exhibit misogynism, though it's more commonly seen in men or in male-dominated industries or governments. The mis part of the word comes from the Greek miso, which means "hate." In misogynism it's added to the Greek gyne, "woman" or "queen," and the doctrine suffix -ism.