Panahong nararansan sa mababang latitude a. Tag-ulan at tagsibol
b. tag ulan at tag init
c. Tag-araw at tag-ulan
d. Tagtuyo at tag-ulan

Mitochondria produce atp, a high energy compound. atp is used for all sorts of enzyme-mediated reactions, such as making proteins/nucleotides/etc, certain compounds cross the cell membrane, muscles move, etc.  without this source of energy, a cell will die. it will not be able to repair itself, defend against pathogens, etc.