Year 10 Biology Practice Test 2025 – Full Study Resource

Endocrine glands primarily function to secrete hormones directly into the bloodstream. Hormones are chemical messengers that travel throughout the body and regulate various physiological processes, including metabolism, growth, reproduction, and mood. This process allows for communication between different parts of the body and helps maintain homeostasis— the body's stable internal environment.

Different endocrine glands, such as the pituitary, thyroid, and adrenal glands, each produce specific hormones that carry out unique functions. For instance, insulin from the pancreas regulates blood sugar levels, while hormones from the adrenal glands are involved in the body's response to stress.

The other options represent functions that are not characteristic of endocrine glands. Fighting infections is primarily the role of the immune system, regulating body temperature is mainly managed by the hypothalamus and mechanisms involving sweat and blood flow, and gas exchange is a function of the respiratory system, specifically in the lungs. Each of these systems operates independently of the endocrine system, highlighting the unique and essential role of hormones and endocrine glands within bodily functions.