Q. Give reasons for the following.
A)The backbone is not made of a single long bone.
B) Snakes move in a zigzag manner.
C) Our body has different types of moveable joints.
Answers
Answer:
Snakes have no legs but they show fast movement in a zigzag manner. The movement is carred out by alternating contraction and relaxation of a set of muscles present on the sides of the body creating series of curbves. The wave-like motion pushes the body forward by prassing against the ground.
Answer:
A) The vertebral column is not made of a single bone because a single bone cannot bend. If it would have been made of a single bone, the body could not have shown the movement. Hence, it is the series of vertebrae that extend from the cranium to the coccyx. These bones makes the spine present in it flexible.
B) Snakes have no legs, yet they can move very fast. If you watch a snake slithering, you will see that it usually moves in a zigzag manner. It does this by alternately tightening and relaxing a set of muscles along each side of its body. This produces horizontal waves, which let it move forward in a zig...
Hope it helps you...