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प्रश्न
Why have reflex arcs evolved in animals?
उत्तर
Reflex arcs have evolved in animals primarily because the thinking process of the brain is not fast enough to respond immediately to certain stimuli that require quick action for survival or response.
Many animals, especially simpler ones, lack a complex neuron network capable of fast thinking. Reflex arcs provide a more efficient way of functioning by enabling quicker responses to stimuli, bypassing the slower thinking processes.
This efficiency is vital for survival, allowing animals to respond instantly to dangers or other important stimuli. Even in animals with complex neural networks, reflex arcs remain crucial for ensuring immediate and efficient responses.
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संबंधित प्रश्न
How do we detect the smell of an agarbatti (incense stick)?
When you smell a favourite food your mouth begins to water (that is, you secrete saliva). Write down what is the example of the smell of the food?
Which of the following helps in maintaining posture and balance of the human body?
When we touch a hot plate unknowingly, then this heat is sensed by a receptor P present in our fingers. The receptor triggers and impulse in neuron Q which transmits the message to an organ R which is a part of the central nervous system. Here the impulse is passed on to a neuron S which in turn passes it to a yet another neuron T. The neuron T passes the impulse to a tissue U in our arm. The tissue U then contracts and pulls our hand away from the hot plate.
(a) What is the name of (i) receptor P (ii) neuron Q, and (iii) organ R?
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(d) What name is given to the phenomenon in which hand is pulled away quickly from the hot plate?
(e) Name the effector in this whole process.
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(a) impulse travels in the motor fibre
(b) impulse travels in the sensory fibre
(c) effector organ stimulated
(d) impulse crosses the synapse
List in tabular form two differences between reflex action and walking.
List in tabular form three distinguishing features between cerebrum and cerebellum.
What is a reflex action?
Explain the following term :
Conditioned reflex
Which of the following is an example of unconditioned reflex?
