<span>The question says, vertebrates have notochord during early embryonic development. The statement is true. A notochord is a cartilaginous skeletal rod which support the body in all embryonic and some chordate animals. It has essential role in vertebrate development. It is a primitive beginning of the spinal cord.</span><span />
It won't move until a kick (outside force) is applied because the rock has more friction it stops the ball more easily.
Increase variation among its offspring.
