OCR GCSE Biology Practice Exam 2026 – Comprehensive All-in-One Guide to Exam Success

The reflexive action in grasping is primarily triggered by the stimulation of the skin in the hand area, specifically when the fingers make contact with an object. When a finger is placed in the open hand of a baby, the sensory receptors in the skin are activated, leading to a grip reflex. This reflex action occurs because the brain interprets the touch as a signal to grasp, a response that is essential for newborns as it helps them cling to their caregiver.

Pulling a finger away from an open hand expresses the natural reaction of the baby's focus on grasping. The other options relate to different types of stimuli that do not specifically engage the grasping reflex. For instance, a loud noise might startle a baby, but it does not directly lead to the grasping action. Similarly, touching the baby's feet or placing a finger in the mouth may provoke other reflexes but are not the primary drivers for the grasp reflex. Thus, the action of a finger being pulled away effectively illustrates the reflexive nature of this specific grasping response in infants.