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A chemical messenger carried in the blood from a gland to target cells or organs.

A chemical messenger released by a gland and carried in the blood to produce an effect at a target organ.

One way it does this is through the endocrine system: a group of glands that secrete chemical messengers called hormones directly into the bloodstream. The blood carries a hormone around the body to a target organ, where it produces an effect. Although the hormone circulates widely, only cells able to respond to that particular hormone act on its message.

A chemical messenger carried in the blood from a gland to target organs, where it produces an effect.

If asked why the pituitary is called the ‘master gland’, explain that some of its hormones stimulate other glands to release hormones; do not just state its nickname.

Keep the route clear: endocrine gland → hormone in the bloodstream → target organ → effect.

On a hormone graph, identify the hormone from the shape and timing of its peak: the sharp LH surge occurs at about ovulation, whereas progesterone rises mainly after ovulation.

A chemical messenger released by a gland into the blood and carried to parts of the body where it has an effect.

A chemical messenger produced by endocrine cells and carried in the blood to cells with the appropriate receptors.

The endocrine system provides one form of communication. Its endocrine glands produce chemical messengers called hormones.

A chemical messenger produced by a gland and carried in the blood to target cells or organs.

A chemical messenger produced by a gland, carried in the blood and able to alter the activity of cells with compatible receptors.

The endocrine system provides this coordination using hormones. It is made up of hormone-producing glands located in different parts of the body. Hormones help regulate many processes, including growth, metabolism, blood glucose concentration and reproduction.

A chemical messenger released into the blood that affects cells or organs able to respond to it.

A chemical messenger made by an endocrine gland and carried in the blood to cells with the appropriate receptors.

A chemical messenger carried in the blood to target cells or organs, where it produces an effect.

A chemical messenger released into the blood that acts on particular target cells or organs.

A chemical messenger secreted by a gland and transported in the blood to cells with the appropriate receptor.

The endocrine system coordinates many responses to these changes using chemical messengers called hormones.

A chemical messenger secreted by an endocrine gland, carried in the blood and able to affect target cells with the appropriate receptors.

A chemical messenger made by a gland, carried in the blood and able to affect target cells with the appropriate receptors.

A chemical messenger secreted by a gland and transported in the blood to cells with the appropriate receptors.

Hormone

Definition

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AQA GCSE Biology · 8461

Exam tips

Revise Biology with GradeGen

Edexcel GCSE Biology · 1BI0

OCR GCSE Biology A · J247

OCR GCSE Biology B · J257