Final answer:
The pelvis supports the upper body and transfers weight to the lower limbs. It also serves as an attachment point for muscles and protects internal organs.
Step-by-step explanation:
The pelvis serves several important functions in connection to the trunk and lower extremities. Its primary role is to support the weight of the upper body when sitting and to transfer this weight to the lower limbs when standing. The pelvis also serves as an attachment point for the muscles of the trunk and lower limbs, and it protects the internal pelvic organs. Additionally, the pelvis helps maintain the body's center of gravity and provides a strong foundation for stability and movement.