Final answer:
Organisms that float and cannot swim against the currents are known as plankton, which includes both phytoplankton and zooplankton. Phytoplankton are photosynthetic bacteria and algae, while zooplankton are tiny animals that consume phytoplankton.
Step-by-step explanation:
Organisms that float and cannot swim against the currents are known as plankton. More specifically, these organisms can be classified as phytoplankton, which are bacteria and algae that use sunlight to make food, or as zooplankton, which are tiny animals that feed on phytoplankton. Unlike nekton, which can swim through the water on their own, and benthos, which crawl in sediments at the bottom of the water, plankton are carried by water currents.
To answer the question, the correct options from the given choices would be both 1) Phytoplankton and 2) Zooplankton, as they both represent types of organisms that float and cannot swim against the currents.