February 8, 2015

10th Class Biology Control and Coordination - Important Questions

Q: Reaching for a pencil, grasping a doorknob, walking or running, driving etc., involve some movements. What are they?
A: Whenever we move the three basic functions, movement, balance, and coordination work together to produce purposeful motions of body parts.

Q: Give some examples of responses to stimuli.
A: The cat may be running because it has seen a mouse.
Plants grow out into the sunshine.
We start sweating when it is hot and humid.

Q: Imagine yourself to be Galan, the Greek physiologist (A.D. 129-200). One day a patient came to you and told that he had fallen from his chariot
and had a blow in the neck. He complained of loss of feeling in the arm while still retaining normal muscular control of its moment. What questions would arise in your mind to make any conclusions about the situation?

A: If I were Galan, I would think on following questions:
1. Is it the nervous system that is damaged?
2. Why is it that the blow in the neck resulted in the loss of feeling?
3. If the nervous system is affected, how is it that there is normalcy in muscular control of its movement?
4. Are there different types of nerves for feeling and muscular movement?
5. What should I do to the patient to normalize his situation?

Q: Touch the leaves of Mimosa pudica (Touch me not plant) and observe how the leaves respond. Write your observations.
A: I went into a botanical garden and observed Mimosa pudica. When I touched the leaves of the plant, I observed that the plant folded up its leaves. Then I observed the plant carefully and noted down my observations:


Mymosa pudica leaves has pad like swellings at the base. Here cells contain lot of water and large inter cellular spaces. Due to water pressure pulvini hold the leaf erect. Touch me not plant shows nastic movement by touch. This is called thigmo nasty.

When we touch the leaves an electrical impulse is generated. This impulse acts on plant hormone. Because of this hormone water in the pulvini cells which are closer to the leaf vein migrate to other side of the cells then pulvini loss its firmness leaves become fold. After 20 to 30 minutes water comes back. pulvini gets firm and leaves become erect.

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