Concept: Muscles:Soft contractile tissues present in the human body that supports the movement of different parts of the body are called muscles. Muscles are attached to the bones by means of tendons. Bones: The body's internal structure is the Human skeleton. This is made up of 300 bones at birth-this number falls by adulthood to 206 bones as certain bones have fused. In the skeleton, the bone mass reaches maximum density around age 30. Cartilage: Bone and cartilage are formed from skeletal connective tissue. Blood and lymph are formed from fluid connective tissue. The difference between bone and cartilage is that bone is hard while cartilage is soft. Bones are the major part of the skeleton in the body, while the cartilage forms the ears, rib nose, etc. Rib cage: The ribs are long curved bones, part of the axial skeleton, which form the rib cage. Human rib cage consists of the 24 bones. They serve to protect thorax's lungs, heart, and other internal organs. All ribs are attached to the thoracic vertebrae at the back and are numbered 1–12 by the vertebrae to which they are attached. Explanation: The correct match is as given: (a) Helps in the movement of body by contraction and relaxation. (ii) Muscles (b) Hard structure which forms the skeleton (iv) ​Bones (c) Part of skeleton which can be bent (i) Cartilage (d) Joins the chest bone and backbone together to form an enclosure (iii) Rib-cage (a) - (ii), (b) - (iv), (c) - (i), (d) - (iii) Additional Information The human skeleton is made up of 206 bones, including bones of the: The femur (the thigh bone) is the largest bone in the human body whereas the stapes (bone of ear) is the smallest bone of the body. Skull: including the jaw bone Spine: cervical, thoracic and lumbar vertebrae, sacrum and tailbone (coccyx) Chest: ribs and breastbone (sternum) Arms: the shoulder blade (scapula), collar bone (clavicle), humerus, radius and ulna Hands: wrist bones (carpals), metacarpals and phalanges Pelvis: hip bones Legs: the thigh bone (femur), the kneecap (patella), shin bone (tibia) and fibula Feet: tarsals, metatarsals, and phalange