Answer:
Their ability to manufacture their own food
Step-by-step explanation:
There are two main types of plankton. this includes phytoplankton and zooplankton. Phytoplankton are different from zooplankton in that these plankton are plant-like and undergo photosynthesis manufacturing their own food. They are also regarded as being autotrophic. They are important in that other organisms including the zooplanktons depends on them for food, hence they can also be categoriZed as producers.