Question

Choose the correct answer from each of the four options given below:

Which of the following is not a natural reflex action

• A. Knee jerk
• B. Blinking of the eye due to strong light
• C. Salivation at the sight of food
• D. Sneezing when an irritant enters the nose

Answer 1

The correct option is C

Salivation at the sight of food

The correct option is (C)

Explanation of correct option:

1. Natural reflexes are those which we have not acquired through previous experiences, or it does not require any prior knowledge and are just present from our birth.
2. Some examples of reflexes are:

1. When light acts as a stimulus, the pupil size of our eyes changes.

2. Sudden withdrawal of hand or leg when pricked with a needle.

3. Cough or sneeze.

4. Knee jerks in response to a leg kick

Explanation of incorrect option:

Option (A): Knee jerk-

1. It is a type of patellar reflex as well as a natural reflex as it is caused by the striking of the knee tendon.
2. And this contraction is coordinated with the relaxation of the hamstring muscle, making the leg kick.

Option (B): Blinking of the eye due to strong light -

1. It is both voluntary and involuntary action.
2. As we can blink our eyes if we want, i.e., voluntary action
3. Our eyes also can blink without thinking about it, i.e., involuntary action.

Option (D): Sneezing when an irritant enters the nose -

1. This is a natural reflex as it occurs because of the stimulation of the respiratory tract.

Final Answer:

Salivation at the sight of food is not a natural reflex action.