Labels:text | font | screenshot | black and white | white OCR: One of the most commonly recognized traits is sex. It divides the biological world into two discrete categories; moreover, the number of males and females in each species is about equal. Since Aristotle, many hypotheses have been proposed to explain the basis of sex, but not until sex chromosomes were discovered in the early 1900's was the true mechanism of sex determination understood. Learning that inheritance of a particular trait (sex) is associated with inheritance of a distinct pair of chromosomes was of critical importance in proving that genes are located on chromosomes.
