There are over 800,000 named species in the Phylum Arthropoda, named from the Greek arthros (= jointed) and poda (= foot), including the familiararachnids, crustaceans, and insects, together with a host of less familiar critters, like centipedes, millipedes and sea spiders. All arthropods have jointed appendages.

Jointed appendages are specialized structures found in certain organisms that are used for movement and locomotion. Insects, the correct answer to this question, have jointed appendages that allow them to move in a coordinated and efficient manner.

Insects have an exoskeleton, which is a hard outer covering that provides support and protection to their bodies. This exoskeleton is made up of a series of plates or segments that are connected by flexible joints. These joints allow the appendages, such as legs and wings, to move in a wide range of directions.

The jointed appendages of insects have several distinct advantages:

1. Flexibility: The movable joints allow insects to bend and flex their appendages in various ways. This flexibility enables them to navigate through complex environments and adapt to different terrains.

2. Precision: The joints in insect appendages are highly specialized, allowing for precise movement and control. This precision is crucial for activities such as walking, climbing, and grasping objects.

3. Efficiency: The jointed appendages of insects are designed for efficient movement. The segments can be extended or retracted, allowing insects to adjust their stride and conserve energy during locomotion.

4. Specialization: Insects have different types of jointed appendages that are adapted for specific functions. For example, the legs of grasshoppers are designed for jumping, while the legs of beetles are modified for digging. This specialization allows insects to perform a wide range of tasks and exploit different ecological niches.

In addition to insects, other organisms such as crustaceans (e.g., crabs and lobsters) and arachnids (e.g., spiders and scorpions) also have jointed appendages. However, the question specifically asks for the organism with jointed appendages to move, and insects are the best answer in this context.

Overall, jointed appendages are a remarkable adaptation that allows insects to navigate their environment with agility, precision, and efficiency. These structures play a crucial role in the success and diversity of the insect world.