Tag: reflex action and reflex arc basic

Questions Related to reflex action and reflex arc basic

For good reflex actions we require intact _____________.

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. Spinal cord

  2. Medulla oblongata

  3. Hypothalamus

  4. Cerebellum

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Correct Option: A

Which of the following is not a reflex action?

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. Salivation

  2. Sweating

  3. Withdrawal of hand when pinched by needle

  4. None of these

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Correct Option: B
Explanation:

An automatic (involuntary) neuromuscular action excited by a defined stimulus is called reflex action. Sweating is not a reflex action. It is primarily a means of temperature regulation. But, Salivation and hand withdrawal because of the needle both are reflex actions.

Classify the following into reflex action and in voluntary actions of brain.

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. Beating of heart

  2. Withdrawing your hand inmediately on touching a hot object

  3. Change in size of pupil in response to intensity of light

  4. Riding a bicycle

  5. Sneezing

  6. pulling up the leg immediately when foot falls on some sharp object.

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Correct Option: A

Reflex action is the function of brain stem.

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. True

  2. False

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Correct Option: A

The direction of against stimulus response is opposite in which of the following reflex action?

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. Biceps tendon reflex

  2. Knee jerk reflex

  3. Triceps tendon reflex

  4. Withdrawal reflex

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Correct Option: D
Explanation:

Option 'D' is correct


Withdrawal reflex is the reflex that involves the withdrawal is response to stimulus. It is also known as pair withdrawal reflex. When pair receptors are stimulated, reciprocal innervation stimulate the flexons to withdrawal and inhibit the extensors. 

Which one is not a reflex action?

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. Closing the eye lids suddenly

  2. Release of saliva

  3. Obeying the order

  4. Pupillary constriction

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Correct Option: A

Which one is correct about voluntary and involuntary movements?

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. Voluntary movements- caused by skeletal muscle, Involuntary movements- caused by smooth muscle

  2. Voluntary movements- caused by smooth muscle, Involuntary movements- caused by skeletal muscle

  3. Voluntary movements- controlled by brain, Involuntary movements- controlled by organs

  4. Voluntary movements- controlled by organs, Involuntary movements- controlled by brain

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Correct Option: A
Explanation:

Voluntary movements are movements that are in direct control of the will of a person. These are controlled by skeletal muscles. For example walking, talking, dancing, etc. Involuntary movements are movements that are not in control of a person. They are generated by smooth striated muscle. For example, heart pumping, digestion, etc. 

Medulla oblongata controls involuntary functions.
zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. True

  2. False

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Correct Option: A
Explanation:

Medulla oblongata is the part of hindbrain. It is located in the brainstem, anterior to the cerebellum. It controls the involuntary functions . It is linked to the autonomic system and has cardiac, respiratory, vomiting and vasomotor centres. It also controls breathing heart rate and blood pressure.

All movements in response to the environment can be carefully controlled.

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. True

  2. False

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Correct Option: A
Explanation:

Each kind of a change in the environment evokes an appropriate movement in response. When we want to talk to our friends in class, we whisper, rather than shouting loudly. So, the movement to be made depends on the event triggering it. Hence, such controlled movement must be connected to the recognition of various events in the environment, followed by only the correct movement in response. Therefore, the correct answer is option A.

Which of the following statements are true about reflex action?
i. It is a response activated after the activity or incident completes.
ii. It is an involuntary action.
iii. It is the sudden action in response to something in the environment.
iv. Impulse is carried to the brain directly for the response.

zoology control and coordination in living organisms the reflex action reflex action and reflex arc basic reflex action and reflex arc

  1. (ii) and (iii)

  2. (ii) and (iv)

  3. Both A and B

  4. None of the above

Show answer
Correct Option: A
Explanation:

Reflex action is an action which is given in response to something in the environment. It is an immediate action taken without much thinking and it does not have our control. The spinal cord is responsible for the response of the body because the impulse has not reached the brain till then. Therefore, the correct answer is option A.