OCR GCSE Biology 2025 – 400 Free Practice Questions to Pass the Exam

Hormones are primarily released directly into the blood, which is the correct response. This process allows hormones to travel throughout the entire body quickly and efficiently, reaching various organs and tissues where they can elicit specific biological responses. The endocrine glands, such as the pituitary gland, thyroid gland, adrenal glands, and pancreas, are responsible for secreting hormones directly into the bloodstream, ensuring that these signaling molecules can communicate over long distances within the body.

This method of release is essential for maintaining homeostasis, regulating metabolism, growth, development, and the body's response to stress, among other vital functions. Other systems, like the lymphatic or digestive system, do not primarily serve as pathways for hormonal release, and the nervous system is responsible for rapid, short-term signaling through neurotransmitters rather than the long-term, widespread effects characteristic of hormones.