Ecosystems — BIOLOGY STD 12 Science — Question

1. Phytoplankton

Explanation:

Primary production is the synthesis of food through the process of photosynthesis, which uses light as its source of energy. The primary production in the ocean is performed by free-living microscopic organisms called phytoplankton. Larger autotrophs, such as the sea grasses and seaweeds are generally confined within the photic zone. The majority of free-floating production takes place within microscopic organisms (phytoplankton)