Heart muscle cells have alot of mitochondria. why do you think this is?

The heart is a vital organ with a high metabolic demand. Our heart muscles contain so much mitochondria because those muscles are very active in our body and require lots of energy to constantly pump blood through our circulatory system.

Explanation:

a axis of a graph is a color or shade so we can all go outside and have a party so we can eat   some grilled cheese sammiches and broccoli and have some ugly fun times

i don't know why i put this, i know its not the i was just bored : p

delete this answer while you can

answer; i believe the answer is (polygenic inheritance;