(a) What is a hormone?
(b) Outline the role played by adrenaline in an emergency situation.
(c) In a tabular form, list five differences between hormonal co-ordination and nervous co-ordination.
(d) Name three animal hormones and two plant hormones.
(a) A hormone can be defined as a chemical substance produced in small quantities by endocrine/ductless glands and carried to all other parts of the body/target organs by blood stream/vascular system, where it produces/exerts a response.
(b) Role of adrenaline in an emergency: -
(c) Differences between hormonal co-ordination and nervous co-ordination
| Hormonal co-ordination | Nervous co-ordination |
| Involves transmission of chemicals | Involves transmission of electrical impulses and chemical substances by the nervous system |
| Response to stimulus is slower | Response to stimulus is faster |
| Hormones are secreted into the blood and carried to any part of the body | Nerve impulses are transmitted to a particular location/target organ by a particular set of neurons |
| The target is usually far away from the site of production | Target organ maybe near or far |
| Response may last for a long time | Response are short lived |
| secretion of hormones and their actions are involuntary | nervous actions and their responses are voluntary and involuntarily |
| Hormonal co-ordination occurs in both plants and animals | Nervous co-ordination occurs only in animals |
(d)(1) Animal Hormones: -
(ii) Plant Hormones: -
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