Heat is
a. when energy is destroyed.
b. the flow of energy caused by temperature differences.
c. when energy is created.

the flow of energy caused by temperature differences

In physics, the law of conservation of energy states that the entire energy of a separate system remains fixed, it is stated to be maintained over time. This law suggests that energy can neither be created nor destroyed; preferably, it can only be modified or shifted from one form to another.

the pic attached shows the stages of mitosis. hope it !

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.