My talk will have two parts on two different active biological systems. First, I will tell you how a single cell produces light to survive; then, I will explain how a huddle of chloroplasts in cells reacts to light to optimize plant life. Part I: Bioluminescence (light generation in living organisms) has mesmerized humans since thousands of years ago. I will first go over the recent progress in the physics of single-cell bioluminescence (PRL 125 (2), 028102, 2020) and then will go beyond and present a lab-scale model of bioluminescent breaking waves. Part II: To remain efficient during photosynthesis, plants can re-arrange the internal structure of cells by the active motion of chloroplasts. I will show that the chloroplasts can behave like a densely packed light-sensitive active matter, whose non-gaussian athermal fluctuations can lead to various self-organization scenarios, including active glassy dynamics under dim lights (PNAS 120 (3), 2216497120, 2023).