Final answer:
An unconditioned reflex is an instinctive and involuntary response to a specific stimulus. Three examples of unconditioned reflexes in humans are the s-u-c-k-i-n-g reflex, grasp reflex, and knee-j-e-r-k reflex.
Step-by-step explanation:
An unconditioned reflex is an instinctive and involuntary response to a specific stimulus. It occurs without prior learning or conditioning. Three examples of unconditioned reflexes in humans are:
- Sucking reflex: Newborn babies instinctively suck on a nipple placed in their mouth.
- Grasp reflex: Babies instinctively grasp an object placed in the palm of their hand.
- Knee-j-e-rk reflex: When a doctor taps the patellar tendon below the kneecap with a rubber hammer, it elicits the reflex of extending the leg at the knee.