Final answer:
Freely moving bones are known as synovial joints, which allow for a wide range of motion, whereas fixed bones are part of immobile joints like fibrous joints. Cartilaginous joints like synchondroses and symphyses allow for very limited movement and are connected by cartilage.
Step-by-step explanation:
Freely moving bones are synovial, while fixed bones are fixed. The correct answer to the fill-in-the-blank question is c) Synovial, Fixed. Synovial joints are the only joints that have a space, or "synovial cavity," between the adjoining bones allowing for a wide range of motion, thus classifying them as diarthrosis according to functional classification. These types of joints allow for angular and rotational movements and are primarily found in the appendicular skeleton, facilitating movements in one or multiple anatomical planes. On the other hand, fixed joints such as fibrous joints, like sutures in the skull, are immobile and functionally classified as synarthrosis.
Contrarily, cartilaginous joints, including synchondroses and symphyses, are types of joints where the bones are connected by cartilage, allowing very limited movement. Synchondroses are joined by hyaline cartilage and found in growing children's epiphyseal plates, whereas symphyses have a fibrocartilage connection and are between vertebrae. Both are functionally classified as either synarthrosis or amphiarthrosis (slightly movable joints).