The relationship between the insect hormones ecdysteroid and PTTH is an example of a. an interaction of the endocrine and nervous systems. b. homeostasis achieved by positive feedback. c. homeostasis maintained by antagonistic hormones. d. competitive inhibition of a hormone receptor.

Verified step by step guidance

1. Identify the roles of ecdysteroid and PTTH: Ecdysteroid is a steroid hormone that promotes molting and metamorphosis in insects. PTTH (Prothoracicotropic hormone) stimulates the prothoracic glands to produce ecdysteroids.
2. Understand the interaction: PTTH, produced by neurosecretory cells in the brain, acts on the prothoracic gland to trigger the secretion of ecdysteroids, linking the nervous system (source of PTTH) and the endocrine system (source of ecdysteroids).
3. Analyze the options: Option (a) suggests an interaction between the endocrine and nervous systems, which aligns with the roles of PTTH and ecdysteroids as described.
4. Eliminate other options: Option (b) is incorrect as the process is not described as a positive feedback loop. Option (c) is incorrect because PTTH and ecdysteroids are not antagonistic; they work in a sequence to achieve a common goal. Option (d) is incorrect as there is no competitive inhibition involved in their interaction.
5. Conclude with the correct answer: Based on the analysis, the correct answer is (a) an interaction of the endocrine and nervous systems.

Key Concepts

Ecdysteroid and PTTH

Ecdysteroids are steroid hormones that regulate molting and metamorphosis in insects, while PTTH (Prothoracicotropic Hormone) is a neurohormone produced in the brain that stimulates the production of ecdysteroids from the prothoracic glands. This relationship exemplifies how hormones can interact to control physiological processes, particularly in the context of growth and development.

Endocrine and Nervous Systems Interaction

The endocrine system consists of glands that secrete hormones into the bloodstream, while the nervous system transmits signals through neurons. The interaction between these two systems is crucial for regulating various bodily functions, including growth and stress responses, highlighting how hormonal signals can be influenced by neural inputs, as seen with PTTH's role in ecdysteroid release.

Homeostasis

Homeostasis refers to the maintenance of stable internal conditions in an organism despite external changes. In insects, hormonal interactions, such as those between ecdysteroids and PTTH, play a vital role in achieving homeostasis by regulating processes like growth and development, ensuring that the organism can adapt to its environment effectively.