Because Precambrian rocks are in short supply, hence fossil evidence is harder to find.they only discovers sections of some Precambrian rocks there were no bones or shells to be permineralized.
By contracting, muscles pull on bones and allow the body to move. ... Each muscle in the pair works against the other to move bones at the joints of the body. The muscle that contracts to cause a joint to bend is called the flexor. The muscle that contracts to cause the joint to straighten is called the extensor
Explain what you mean and I can try and help
physiology
Explanation:
physiology is the branch of science concerned with the function of body parts as a whole
Having a messy work station
