IB Biology: B3.3-Skeletons as Anchorage and Levers

Front

What is a skeleton?

Back

A skeleton is a hard framework to which muscles are attached and also acts as levers.

Front

What is a lever in the context of the skeletal system?

Back

A lever is a rod or bone that is able to rotate about a fixed point or fulcrum.

Front

What are the two types of skeletons found in animals?

Back

Animals either have an endoskeleton or an exoskeleton.

Front

Where are exoskeletons located and what are they composed of?

Back

Exoskeletons are on the outside of the body, consist of plates, and are composed of chitin.

Front

Where are endoskeletons located and what are they composed of?

Back

Endoskeletons are internal, consist of bones, and are composed of calcium phosphates.

Front

Which animals have an exoskeleton?

Back

Arthropods such as spiders, insects, and crustaceans have a tough exoskeleton made of tough plates of chitin.

Front

Which animals have an endoskeleton?

Back

Vertebrates such as dogs, humans, lizards, etc., have an endoskeleton with muscles attached to bones to allow movement.

Front

What is the role of muscles in the skeletal system?

Back

A muscle is typically attached to two parts of the skeleton: the insertion, where the muscle causes movement, and the origin, which is fixed.

Front

How do bones act as levers in the body?

Back

Many bones in the body act as levers, maximizing the efficiency of movement. The application of a little effort on one side of the fulcrum causes greater movement on the other side.