Concept 6: Gene pairs associate and then separate during gamete formation

This idea is essentially Mendel’s first law of genetics, the Principle of Segregation. Again, it is remarkable that Mendel proposed the idea from inference and not from direct observation of gene pairs separating during meiosis. Now we know that gene pairs associate and separate because genes are a part of chromosomes and chromosomes pair and separate during meiosis (Fig. 9).


Figure 9. The principle of segregation is the idea that paired genes separate when gametes are formed. (Image by P. Hain)