Which of the following is NOT a characteristic of tropic hormones?

Tropic hormones are specialized hormones that primarily initiate and regulate the activity of other endocrine glands, playing a crucial role in the endocrine system's communication. The defining characteristics of tropic hormones include their ability to stimulate other endocrine glands (which aligns with the first option), their production in response to regulatory feedback mechanisms (often negative feedback), and their general function as signaling molecules within the endocrine system.

However, stating that tropic hormones are secreted by target organs is incorrect; instead, they are secreted by specific endocrine glands, such as the pituitary gland. Target organs respond to the tropic hormones by producing their own hormones, but they do not secrete tropic hormones themselves. Thus, the focus on the role of tropic hormones being produced by the endocrine glands emphasizes their function in the regulation of other endocrine pathways, differentiating their role from that of the organs they affect.