When a pitcher is holding a baseball, the ball has <u>potential</u><u /> energy.
(The ball is at a rest.)
After the pitcher throws the ball, the ball has <u>kinetic</u><u /> energy.
(The ball is no longer at rest and is in motion.)
Natural selection only occurs when populations have heritable variation.
Cell division and differentiation first begins during the germinal stage of prenatal development.
<u>Explanation:</u>
The development of the zygote into a full developed fetus occurs in three most prominent stages they are the germinal stage that occurs from the conception to the second week.
The embryonic stage that is from second week to the eighth week and the fetal stage that is from the eighth week till the birth of the baby. Each stage has its characteristic development that has to be completed.
