AP BIOLOGY

Detailed explanation-1: -They play a vital role in aquatic ecosystems by forming the energy base of the food web for all aquatic organisms. As autotrophic organisms, algae convert water and carbon dioxide to sugar through the process of photosynthesis.

Detailed explanation-2: -Producers. Primary producers-including bacteria, phytoplankton, and algae-form the lowest trophic level, the base of the aquatic food web. Primary producers synthesize their own energy without needing to eat. Many photosynthesize, using the sun’s energy to build carbohydrates.

Detailed explanation-3: -Most algae possess chlorophyll a. As primary producers, they use the sunlight energy to convert inorganic substances into simple organic compounds, and, provide the principal basis of food webs on the Earth. Furthermore, they produce oxygen that is essential for heterotrophic organisms.

Detailed explanation-4: -They turn carbon dioxide into biomass and release oxygen. Ecologically, algae are at the base of the food chain. They are the beginning of the transfer of solar energy to biomass that transfers up trophic levels to the top predators. Phytoplankton, are largely responsible for this primary production.