biology HELP

I have a few question that I really don't understand at all, so anyone who knows about science biology can to please message me and HELP ME OUT?
thanks in advance

1. Functions of the skeletal system:
* supports the body
* facilitates movement
* protects internal organs
* produces blood cells
* stores and releases minerals and fat
the structure is directly linked to the function- it provides a framework to support the body; holds it upright etc. ribcage protects vital organs, different types of joints within the structure aid movement, cavities within the bones are a space for production of cells

2.
* Ball and socket joint– This kind of joint involves two bones. One of the bone has a large rounded end which fits into a cup-like socket of the other bone. This kind of joint is generally found in large bones such as the shoulder joint and hip joint. A ball and socket joint provides the greatest degree of movement among different kinds of joints including rotation, flexion, extension, abduction, and adduction.
* Hinge joint-This joint is said to be a very simple joint that allows movement only in one axis. It allows only two kinds of movements- flexion and extension. Example of this joint is the joints found between in the elbow and knee.
* Pivot joint– This type of joint allows rotation along one axis only. A common example of this type of joint is the atlantooccipital joint in the neck.
* Ellipsoid/gliding joint– This joint is very similar to the ball and socket joint but without rotation. It allows movements only in two axes. Example of this is the wrist joint.



Goodluck on 3,4,5