7. Control and Coordination | Introduction Science class 10
7. Control and Coordination | Introduction Science class 10
Introduction
Chapter 7. Control and Coordination
All living organisms respond to various stimuli like heat, light, cold, touch, pressure etc.
Example : Withdrawal of hand on touching a hot object.
Control and Coordination in Animals:
It is brought about in all animals with the help of two main systems
(a) Nervous System
(b) Endocrine System
Functions of Nervous System
(i) To receive the information from environment
(ii) To receive the information from various body parts.
(Stimuli → Response)
(iii) To act accordingly through muscles and glands.
1. Stimulus : Any change in environment to which the organisms respond is called stimulus. E.g., touching a hot plate.
2. Response : The reaction of our body to a stimulus. E.g. withdrawal of our hand on touching hot plate.
3. Receptors : Are specialised tips of some nerve cells that detect the information from the environment.
Type of Receptors :
(i) Photo receptor : for vision (Eye)
(ii) Phono receptor : for hearing (Ear)
(iii) Gustatory receptor : for taste (Tounge)
(iv) Olfactory receptor : for smelling (Nose)
(v) Thermo receptor : for for feeling heat (skin)
These receptors are usually located in our sense organs, such as the inner ear, the nose, the tongue, and so
on.
Nervous Tissue: nervous tissue is made up of an organised network of nerve cells or neurons, and is specialised for conducting information via electrical impulses from one part of the body to another.
Nervous cell (neuron) : The unit of nervous tissue is called nevous cell or neuron.
Structure of neuron:
Functions of nervous cell or neuron:
Nervous cell or neuron is specialised for conducting information via electrical impulses from one part of the body to another.
The parts of nervous cells:
(i) Dendrite : Where informations are acquaired at the end of the dendritic tips of a nerve cell.
(ii) From Dendrite to cytoplsm : Here the the impulse travels from the dendrite to the cell body, and then along the axon to its end.
(iii) Axon : At the end of the axon, the electrical impulse sets off the release of some chemicals. These chemicals cross the gap, or synapse, and start a similar electrical impulse in a dendrite of the next neuron.
Propagation of informations through nerves :
All informations to our brain that delivers the informations that are acquaired at one end of dendritics of the nerve cell and sets off a chemical reaction that creates an electrical impulse. This impulse travels from the dendrite to the cell body, and then along the axon to its end. At the end of the axon, the electrical impulse sets off the release of some chemicals. These chemicals cross the gap, or synapse, and start a similar
electrical impulse in a dendrite of the next neuron.Such informations are transmitted from one place to another place of the body.
Synapse: The space between two neurons is called synapse.
Reflex Actions
Reflex actions:
Sudden responding of body againt any stimuli like heat, cold, touch, and light without interrencing of mind is called reflex action.
These actions are automatically which occur without the conscious choice of organisms.
Some Examples:
- Pulling the hand back from the flame reflexly.
- Our mouth staeting watering to see food when we feel hungry.
- Closing eyesight on high light.
- Moving out the hand suddenly on pinching of needle.
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The timing and amount of hormone:
The timing and amount of hormone released are regulated by feedback mechanisms. For example, if the sugar levels in blood rise, they are detected by the cells of the pancreas which respond by producing more insulin. As the blood sugar level falls, insulin secretion is reduced.
Assignment
Very Short Type Questions and Answers:
Q1: Name the two substances which are responsible for the control and coordination in plants.
Q2: What are nastic movements? Give one example.
Q3: What are the different Hormones found in Plants and their functions?
Q4: What are receptors? What type of receptors detects smell and taste?
Q5: How the information is send to brain in animals?
Q6: What is cranium?
Q7: How are tissues protected in a brain?
Q8: What is role of brain in reflex action?
Q9: What happens at the synapse between two neurons?
Q10: What is stimulus?
Long Type Questions and Answers:
Q11: What are the different types of nervous systems found in human body? Mention the functions of each.
Q12: Draw the schematic diagram of reflex arc. Define reflex action with suitable example.
Q13: Draw the labeled structure of human brain.
Q14: What are the four main parts of the fore brain? Give the function of each part.
Q15: What are the three parts of the mid brain and their functions?
Q16: Which part of the human brain is responsible for: Intelligence and Memory, Adjustment, movement and Posture, Smell?
Q17: Give the role of Frontal lobe, temporal, lobe and medulla oblongata.
Q18: Name the different lobes found in the fore brain and give their functions.
Q19: What is geotropism?
Q20: What are plant hormones?
Q21: What are controlled movements? How this process happens?
Q22: What are electrical impulses? What re its limitations?
Q23: How the stimulated cells overcome the limitations of electrical impulses?
Q24: How do auxins promote the growth of a tendril around a support?
Q24: Which hormone is responsible for the wilting of leaves in plants?
Q25: What are hormones? Who coined the term hormones?
Q26: What is function of adrenaline? Explain briefly?
Q27: Why diabetes is happen? What is insulin?
Q28: Draw the diagram showing endocrine glands in a male body/female body and label: Pituitary, Thyroid, Adrenal, Testis/ovaries, Thalamus, and Hypothalamus.
Q29: Name the hormone associated with a) Reduction of blood glucose in the body b) Overall metabolism of the body.
Q30: Write the function of testes & ovaries.
Q31: What is function of pituitary gland?
Q34: What is need of control and coordination in the body?
Q35: Which is the structural and functional unit of nervous system? Describe with the help of a diagram.
Q36: “Nervous and the hormonal system together perform the function of the control and coordination in the humans”. Justify.
Question Bank
Very Short Answers (1 Mark)
1. Where is auxin synthesized in plants?
2. Which gland is known as Master gland?
3. Name the hormone that regulates blood sugar level.
4. What is synapse?
5. What are tropic movements? Give one examples
6. Which part of brain is responsible for maintaining posture and balance of our body?
7. Which hormone has inhibiting effect on growth of plants.
8. What is phototropism?
9. What are the components of central Nervous System?
10. What happens at synapse between two neurons?
Short Answers (2 Marks)
1. Draw diagram of neuron and label cell body, dendrites and axon.
2. What is reflex arc? Explain with the help of a flow-chart.
3. Mention one function of each of the following
(i) Cerebellum
(ii) Pons.
4. What is the cause of diabetes? How can it be controlled?
5. Why is it advisable to use iodised salt?
6. Name the different receptors present in our body and write their functions.
7. What are plant hormones? Name a plant hormone that promotes growth in plants.
8. What are sensory and motor neurons? Write their functions.
9 Why is Abscisic acid called a stress hormone?
10. Explain bending of a plant stem towards light by the action of auxin hormone.
Short Answers (3 Marks)
1. What is the significance of tropic movement in plants? Explain any two types of tropic movements.
2. (i) What are endocrine glands?
(ii) Name a gland which has both endocrine and exocrine functions. Also write its endocrine and exocrine secretions.
3. Which hormone is known as emergency hormone in our body? How does it help in coping during emergency?
Long Answers (5 Marks)
1.
(a) Define hormones.
(b) Name any four endocrine glands and the hormones secreted by them.
(c) Name the hormones required for the following :
(i) development of moustache and beard in male
(ii) Lowering of blood glucose.
2. Mention the functions of :
(a) Fore brain
(b) Mid brain
(c) Hind brain
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