Reflex Arc and Reflex action

Q.

In an event of hand touching a hot object and taken back immediately, ________acts as a receptor and _____acts as effector organ.

1. Muscles, skin

2. Fingers, Upper arm

3. Hand, hand

4. Skin, muscles

Q.

An automatic response without the involvement of the brain is called ________.

Q. When we smell tasty food our mouth waters. Which part of the nervous system makes this happen?

Q.

When we touch the leaves of a touch-me-not plant, they begin to fold up and droop. What kind of movement is observed here?

1. Growth dependent

2. Growth independent

3. Directional movement

4. Touch independent

Q.

The response in a reflex action is______

1. Very Slow

2. Fast

3. Regular

4. Very fast

Q. How do you appreciate the role of spinal-cord in reflex actions?

Q.

$\begin{array}{cccc}& \text{Components of Reflec Arc}& & \text{Functions}\\ 1& \text{Receptor}& \text{a}& \text{Receives information from efferent nueron and shows appropriate response}\\ 2& \text{Afferent neron}& \text{b}& \text{Carries information from spinal cord to the effector organ}\\ 3& \text{Interneuron}& \text{c}& \text{Process information and Generates response}\\ 4& \text{Efferent Neuron}& \text{d}& \text{Receives information and generates impulses}\\ 5& \text{Effector}& \text{e}& \text{Carries information from receptor to inter neurons in the spinal cord}\end{array}$

1. 1-f, 2-a, 3-b, 4-e, 5-c

2. 1-e, 2-c, 3-a, 4-b, 5-c

3. 1-d, 2-e, 3-c, 4-b, 5-a

4. 1-a, 2-c, 3-d, 4-e, 5-f

Q.

Give biological reason for the following:

The hand automatically shows the direction to turn a cycle without thinking.

Q. Describe the types of reflexes.

Q.

________ is the pathway of impulses to and from the spinal cord.

1. Reflex arc

2. Reflex pathway

3. Reflex route

4. Reflex journey

Q.

What is the role of brain in reflex action? What are the different types of reflexes?

Q.

Playing the harmonium without seeing its reeds is an example of reflex action.

1. True

2. False

Q. Arrange the path taken by an impulse in a reflex arc.

1. Spinal cord
2. Sensory neuron
3. Effector muscle
4. Motor neuron

Q. He had never shown an urge to fly.
(Replace the underlined word with a synonym)

1. Impulse
2. Courage
3. Desire
4. Ability

Q.

Which of the following statements are true?
(i) Sudden reaction in response to the stimulus is called the reflex action.
(ii) Sensory neurons carry signals from the spinal cord to the muscles.
(iii) Motor neurons carry signals from the receptors to the spinal cord.
(iv) The path through which signals are transmitted from a receptor to a muscle or a gland is called a reflex arc.

1. (i) and (ii)

2. (i) and (iii)

3. (i) and (iv)

4. (i), (ii) and (iii)

Q.

Which is the correct sequence of the components of a reflex arc?

1. $\text{Receptors}\to \text{muscles}\to \text{sensory neuron}\to \text{motor neuron}\to \text{spinal cord}$

2. $\text{Receptors}\to \text{sensory neuron}\to \text{spinal cord}\to \text{motor neuron}\to \text{muscles}$

3. $\text{Receptors}\to \text{spinal cord}\to \text{sensory neuron}\to \text{motor neuron}\to \text{muscles}$

4. $\text{Receptors}\to \text{motor neuron}\to \text{spinal cord}\to \text{sensory neuron}\to \text{muscles}$

Q. Identify the parts in the following pathway that leads to the removal of hand on touching a hot object.

1. Effector
2. Spinal cord
3. Afferent neuron
4. Efferent neuron

Q.

Mark the parts labelled in the following diagram.

1. Neuromuscular junction, Cell body, Sensory neuron, Motor neuron

2. Central Nervous System, Electrical impulse, Sensory neuron, Motor neuron

3. Central Nervous System, Electrical impulse, Sensory neuron,
   Motor neuron

4. Receptor, Sensory neuron, Motor neuron, Relay neuron

Q.

Identify the given pathway and label A, B, C, and D.

1. Reflex arc, A - Receptor, B - Sensory neuron, C - Motor neuron, D - Relay neuron

2. Central Nervous System, A - Electrical impulse, B - Sensory neuron, C - Motor neuron, D - Nerve ending

3. Peripheral Nervous System, A - Electrical impulse, B - Sensory neuron, C - Motor neuron, D - Nerve ending

4. Neuromuscular junction, A - Cell body, B - Sensory neuron, C - Motor neuron, D - Axon

Q. You are driving your bicycle at a fast speed. Suddenly, a small boy comes in front of your cycle and without wasting any time in thinking, you immediately apply the brakes and the accident is avoided. What name is given to such an action ?