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

The stepping reflex in babies, also known as the placing reflex, is primarily triggered when their feet touch a flat surface. This reflex is an inherent response observed in infants, typically demonstrating their natural instinct to mimic walking when held upright with their feet in contact with a solid surface. This action indicates an early development of motor skills and coordination, contributing to the practice of walking as they grow.

The other stimuli listed do not directly evoke the stepping reflex. For instance, hearing a loud noise may cause a startle response but does not specifically lead to the stepping action. Similarly, placing a finger in a baby's mouth prompts a sucking reflex, while stroking the cheek may elicit a rooting reflex, both of which are distinct from the stepping reflex. Understanding the specific triggers of reflexes helps highlight the various developmental milestones in infants.