**Question:** All are true about hormone functions except -

A. Hormones are chemical messengers produced by endocrine glands that regulate physiological processes throughout the body.
B. Hormones act on target tissues by binding to specific receptors, activating intracellular signaling pathways, and ultimately altering cellular function.
C. Hormones can be classified into two broad categories: neurohormones and paracrine hormones.
D. Hormones are constantly released at high concentrations, exerting their effects indiscriminately on target tissues.

**Correct Answer: D. Hormones are constantly released at high concentrations, exerting their effects indiscriminately on target tissues.**

**Core Concept:** Hormones are chemical messengers produced by endocrine glands that regulate physiological processes by binding to specific receptors on target cells.

**Why the Correct Answer is Right:** Hormones are indeed essential for maintaining homeostasis and coordinating various physiological functions within the body. They are released in response to specific needs or conditions and act on target tissues by binding to specific receptors, triggering intracellular signaling pathways, and modulating cellular function.

**Why Each Wrong Option is Incorrect:**

**A. Hormones are chemical messengers produced by endocrine glands that regulate physiological processes throughout the body.**
This statement is correct as it highlights the primary role of hormones in regulating body functions and their production by endocrine glands.

**B. Hormones act on target tissues by binding to specific receptors, activating intracellular signaling pathways, and ultimately altering cellular function.**
This statement is also correct, as it describes the mechanism of action of hormones, explaining their mode of action on target tissues.

**C. Hormones can be classified into two broad categories: neurohormones and paracrine hormones.**
This statement is accurate, as hormones can be categorized based on their mode of action and distance they act on target tissues: neurohormones are released into the bloodstream and act on distant target cells, while paracrine hormones act locally on neighboring cells.

**D. Hormones are constantly released at high concentrations, exerting their effects indiscriminately on target tissues.**
This statement is incorrect as it implies that hormones are released constantly at high concentrations without discrimination. However, hormones are usually released in response to specific needs or conditions and act on target tissues by binding to specific receptors, as mentioned in options A and B. This ensures targeted effects rather than indiscriminate actions on target tissues.

**Core Concept:** Hormones play a crucial role in maintaining homeostasis by regulating various physiological processes in the body. They are produced by endocrine glands and act on target tissues through specific receptors, intracellular signaling pathways, and cellular modulation. This ensures targeted effects rather than indiscriminate actions on target tissues.