To control the crossing of traits. He wanted to make sure that certain variables in his experiments remained unchanged. If they had changed, the experiment would have to be scraped and redone.
The correct answer is "to control the crossing of the traits to maintain a pure strain".
Explanation:
Gregor Mendel is considered the father of genetics for his studies of inheritance in pea plants. Mendel studied how the pea plant's traits are transferred trough generations by cross-pollination. However, in nature pea plants are usually reproduced by self-pollination at which the progeny is produced by a single plant. Mendel prevented his plants from self-pollinating to control the crossing of the traits to maintain a pure strain. By doing so, Mendel assured that the only reproducing method that he was studying was cross-pollination.
The tympanic cavity is an air chamber; it contains a chain of movable bones which transmit the vibrations of the tympanic membrane across the cavity to the middle ear.
