Earthworm has a large number of tiny bristle projections. These bristles are connected with muscles, which help the earthworm in fixing parts of its body to the ground.

Middle finger has one bone.

The movement depends on the type of joints which join two bones together. The body parts having ball and socket joint move in all directions while the body parts having hinge joint move only in one direction.

The ways are given below
(i) We can know the shape of human skeleton by feeling it on the back of our body.
(ii) We can also take the X-ray images of skeleton by X-ray machines.

We can bend or move our body parts only at those places where two bones join together. Such places are called joints.
The amount of movement depends on the type of joint, e.g. ball and socket joint allows movement in all directions whereas hinge joint allows only one directional movement.

Yes, plants do other kind of movements. e.g. response to external stimuli like movement of sunflower towards the sun, movement of roots towards water, wrinkling of leaves of touch-me-not plant by touch stimuli, etc.

Our vertebral column is comprised of 31 small bones. These are joined together with soft tissue in the form of cartilage discs. This arrangement makes this bony structures to have some limited movements of the body.
If there is only one long bone instead of many in the vertebral column, the organism will not be able to avail the limited movements which are necessary for the organisms for its survival.

The human skeletal system is made up of 206 bones.
The functions of skeleton system are
(i) Giving shape and support to the body
(ii) Protecting internal organs
(iii) Making movement possible

The body of a cockroach is covered with hard and tough outer covering called exoskeleton. The skeleton of cockroach is called exoskeleton because it is outside the body.

Yes, cartilages are the additional parts of the skeleton that are not as hard as the bones and which can bent. So, we can say that though most of the skeleton is made of bones but it has some cartilages too.

The types of movements seen in each animals are:
(a) Duck - Flying, walking and swimming
(b) Horse - Running and walking
(c) Kangaroo - Jumping and walking
(d) Snail - Creeping
(e) Snake - Slithering
(f) Fish - Swimming
(g) Human being - Walking and running
(h) Cockroach - Walking and flying (shoot distances)

Under earthworm's body, it has a large number of tiny bristler projecting out. The bristles are connected with muscles. The bristles help to get a good grip on the ground.

The streamlined shape of fish helps it to move in water. Skeleton and muscles present in front side of fish move it on one side while tail muscles move the body the other side. This makes a jerk and pushes the body forward. In this way, it moves in water.

An earthworm is called as farmer's friend as it eats its way through the soil thereby loosening the soil. Also, earthworm's body excretes the undigested materials that increase the fertility of soil.

Elbow and knee are not made up of a single bone rather they are made up of two or more bones which are joined to each other by a joint, i.e. hinge joint. This joint along with the muscles helps us to bend the elbow and knee.