Final answer:
After exhibiting the asymmetric tonic neck reflex (ATNR), Nora's body position would be with her left arm and leg extended and her right arm and leg flexed. This reflex, along with others like the Moro and grasping reflexes, is crucial for an infant's survival in the early months, aiding in feeding and protection.
Step-by-step explanation:
The student has asked what the body position of 3-month-old Nora would be after she exhibits the asymmetrical tonic neck reflex (ATNR) by turning her head to the left when her dad approaches and shakes a rattle. The ATNR is a primitive reflex that is typically observed in newborns where turning the head to one side results in the extension of the arm and leg on the same side and the flexion of the limbs on the opposite side. Therefore, when Nora turns her head to the left, her left arm and leg will extend and her right arm and leg will flex, making the correct answer option 2) Extended left arm and leg, flexed right side.
Newborn reflexes like the Moro reflex, grasping reflex, sucking reflex, and ATNR are vital for an infant's survival in the first few months of life. They enable the baby to have instinctive behaviors that promote feeding, such as the sucking and rooting reflexes, and protection, as seen with the Moro reflex which can help a baby to potentially grasp and hang onto a caregiver if sensed falling.