OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What triggers the sucking reflex in infants?

1. Putting a finger in the mouth

2. Touching their cheek

3. Water immersion

4. Feeling a flat surface

The correct answer is: Putting a finger in the mouth

The sucking reflex in infants is primarily triggered by the stimulation of the mouth area, which includes actions such as putting a finger in the mouth. This reflex is critical for feeding, as it allows infants to latch onto their mother’s breast or a bottle to obtain milk. The presence of an object in the mouth stimulates sensory receptors, leading to an automatic sucking action that helps ensure the infant receives nourishment. Touching their cheek can lead to another reflex known as the rooting reflex, where the infant turns their head toward the touch, but this alone does not directly initiate sucking. Water immersion and feeling a flat surface do not directly engage the oral reflexes necessary for sucking. Instead, these scenarios do not provoke the same immediate response related to feeding that placing a finger in the mouth does. Therefore, this context highlights why the action of putting a finger in the mouth effectively initiates the sucking reflex, emphasizing its role in the feeding process.