Final answer:
The longest and heaviest bone in the human body is the femur, or thighbone, which also happens to be the strongest bone.
Step-by-step explanation:
The Longest and Heaviest Bone in the Human Body
The longest and heaviest bone in the human body is the femur, or thighbone. It is also the strongest bone, designed to support the weight of the body and withstand the forces of locomotion. The femur forms the hip joint in conjunction with the pelvis at the proximal end, and at the distal end, it, along with the tibia and patella, forms the knee joint. The tibia, which is the second largest bone, articulates with the femur and transfers the body's weight to the foot.
The fibula, or calf bone, is important for muscle attachment and forms the lateral part of the ankle joint. While the femur is responsible for our ability to walk, run, and jump, it is partnered with other bones like the tibia and fibula to facilitate a wide range of leg movements.