(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.
(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.
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Correct Answer: Option n
Explanation:
(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: -
Any emergency experienced by an animal usually causes a sudden rage/fear/fright
This leads to the release of adrenalin into the blood; which stimulates the sympathetic nervous system and consequently many different organs
The rate of heart beat is increased and there is heavy breathing
Similarly, there is increase in the body blood sugar/conversion of liver glycogen into glucose.
The muscular tone/power is increased/ there is resistance to fatigue, the pupils of the eyes dilate and the visceral muscles are affected, the animal reacts quickly and energetically.
(c) Differences between hormonal co-ordination and nervous co-ordination
(d)(1) Animal Hormones: -
Somatotropic hormone
Prolactin
Gonatotropic
Thyroxine
Thyrotropic hormone
Oxytocine
Anti-diuretic hormone/A.D.H.
Parafhormone
Adrenalin
Insulin
Oestrogen
Progesterone
Testosterone And
rosterone
(ii) Plant Hormones: -
1 AA/indole-3- Acetic acid/Auxin
2-4D/2-4 Dichlorophenoxy
acetic acid
Gibberellins
Cydtokinins/kinins
Abscisie/Absisic acid
Benzoic acid
NAA/Naphthalene acetic acid
IBA/Indolebutryric acid
Ethelene
Vernalin.
(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: -
Any emergency experienced by an animal usually causes a sudden rage/fear/fright
This leads to the release of adrenalin into the blood; which stimulates the sympathetic nervous system and consequently many different organs
The rate of heart beat is increased and there is heavy breathing
Similarly, there is increase in the body blood sugar/conversion of liver glycogen into glucose.
The muscular tone/power is increased/ there is resistance to fatigue, the pupils of the eyes dilate and the visceral muscles are affected, the animal reacts quickly and energetically.
(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: -
Somatotropic hormone
Prolactin
Gonatotropic
Thyroxine
Thyrotropic hormone
Oxytocine
Anti-diuretic hormone/A.D.H.
Parafhormone
Adrenalin
Insulin
Oestrogen
Progesterone
Testosterone And
rosterone
(ii) Plant Hormones: -
1 AA/indole-3- Acetic acid/Auxin
2-4D/2-4 Dichlorophenoxy
acetic acid
Gibberellins
Cydtokinins/kinins
Abscisie/Absisic acid
Benzoic acid
NAA/Naphthalene acetic acid
IBA/Indolebutryric acid
Ethelene
Vernalin.