The carbon and energy requirements of autotrophic organisms are fulfilled by ___________.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Photosynthesis
Autotrophs are organisms that make their own food. Green plants do it by photosynthesis: using the energy of sunlight trapped by chlorophyll, they take carbon from carbon dioxide and build it into glucose, which serves both as their store of energy and as the source of carbon for all their other compounds.
Why the other options are incorrect
Option (1) Photoelectric effect — Incorrect. It is the release of electrons from a metal surface when light falls on it, a process of physics.
Option (3) Photocatalysis — Incorrect. It is the speeding up of a chemical reaction by light acting on a catalyst, such as titanium dioxide.
Option (4) Photovoltaics — Incorrect. It is the direct conversion of light into electricity, as in solar cells.