Consider the following hormones and their role in the workings of the endocrine system: Where the hormone is produced. Hormone(s) secreted. Hormone function. Adrenal glands. Aldosterone. Regulates salt, water balance, and blood pressure.
Sometimes there are tissue-specific mutations that control formation of certain tissues and/or organs. For instance, if mutation affects skin then the skin would be wrinkly/ugly but organism would still develop.
August Weismann disproved, or attempt to disprove the theory of Lamarckism (which states that: the adaptive trait gained by an organism during its life time can transfer to the new generation of organism; in contrast, proponents of this theory states: changes to genes can only be done through natural selection, and the experiences of changes to an organism's genes during its life time does not transfer), by cutting off the tails of mice, for many generations to observe changes to their traits.