What is structure 3, and how does it help sustain life?
A.
Structure 3 is a mitochondrion, which is the site of cellular respiration.
B.
Structure 3 is a chloroplast, which is the site of photosynthesis.
C.
Structure 3 is the nucleus, which is the control center of the cell.
D.
Structure 3 is the cell wall, which gives the cell structural support.