Explanation:
The middle ear is an air-filled cavity that sits between the tympanic membrane and the inner ear. The middle ear also consists of three tiny bones called ossicles , the round window, the oval window , and the Eustachian tube .
The controlled variable is what stays the same . So it’s C . They are given different amounts but the same food.
<span>Fruit flies and pea plants may seem boring and simple, but the basic principles of genetics were worked out using those organisms. Humans follow the same patterns of heredity. First, meiosis independently assorts chromosomes when gametes are made for sexual reproduction. Second, human heredity involves the same relationships between alleles—dominant and recessive interactions, polygenic traits, and sex-linked genes, among others.</span>