CBSE Class 10 Science Important Questions Chapter 7 Control and Coordination Part 5

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5 Marks Questions

1. Compare nervous and hormonal mechanism for control

Ans.

Mechanism for Control
Mechanism for control

Nervous System

Hormonal System

Made of neurons

Made of secretory cells.

Massages transmitted in the form of electrical impulses

Massage transmitted in the form of chemicals called hormones.

Massages transmitted along nerve fibres.

Messages transmitted thought blood stream.

Massages travel very quickly.

Messages travel very slowly.

Effect of massage usually lasts for a very short while

Effect of massage usually lasts longer

Sense organs are receptors as nerve cells located in them receive information.

Glands are effectors which secrete hormones when as and when the brain commands.

2. Mention one function for each of these hormones.

i) Thyroxine

ii) Insulin

iii) Adrenaline

iv) Growth hormone

v) Testosterone.

Ans. (i) Thyroxin – Control overall metabolic rate of the body (carbohydrate, protein and fat metabolism)

(ii) Insulin – Conversion of glucose to glycogen in liver and muscles, thus decreases blood glucose level.

(iii) Adrenalin – increases heartbeat, blood pressure and blood glucose level.

(iv) Growth hormone – Body growth and development of bones.

(v) Testosterone – Development of male sex organ sand secondary sex characteristics like moustache, beard & voice.

3. a) what are hormones?

b) List four characteristics of hormones

Ans. Hormones are chemical substances which are secreted in very less amount by specialized tissues called endocrine glands.

Characteristics of hormones are –

1) They are required in very less amount.

2) Hormones are specific in their function.

3) They act away from the site of production.

4) Deficiency or over secretions of hormones have negative effects in the body.

4. Design an experiment to demonstrate hydrotropism.

Ans. a) Take two glass troughs A and B and fill each one of them two – thirds with soil.

b) In troughs A plant a tiny seedling. In trough B plants a similar seedling and places a clay pot inside the soil.

c) Water the soil in trough A daily and uniformly. Do not water the soil in trough B but put some water in clay pot and leave both the trough for a few days.

d) Now, dig up the seedling carefully form both the troughs without damaging their roots. Observation – Roots of seedling in trough in A is straight. The root of seedling in trough B is bent to the right side i.e., toward the Clay pot containing water.

Demonstrate hydrotropism

Demonstrate Hydrotropism

Demonstrate hydrotropism

Demonstrate Hydrotropism

5. Describe Nervous system in humans.

Ans. Flow chart of Human nervous system

Flow chart of Human nervous system

Flow Chart of Human Nervous System

6. Draw the structure of a neuron and explain its function. Ans. Neuron acquires particular information through dendrite located on its cell body. This information is then passed on to the axon. Finally, axon ending passes the information into next neuron at the synapse. As soon as the impulse reaches the dendrite, an electrical impulse is generated due to certain chemical changes in neuron. When the impulse reaches axon ending some chemicals released which pass on the impulse to next neuron. These chemicals are known as neurotransmitters.

Neuron acquires

Neuron Acquires

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