There are many multicellular organisms. Even protists, such as seaweed, can be multicellular. The only organism that cannot be multicellular is a bacterium.
No it's a Cyanobacteria, prokaryotic cells capable of photosynthesis.
Many species of lobsters eat seaweed. Seaweed provides many of the nutrients the lobster needs to survive and they will supplement their diet with other foods.
many do. the sea otter ties itself up with seaweed to prevent itself from drifting away on the tide while sleeping. the seaweed dragon hides amongst the seaweed, looking so much like the seaweed that predators cannot see it. there are many more creatures that use seaweed, but im not sur eof them right now.
Mainly unicellular.. But have been known to have a couple or many cells-pluricellular!!
Organisms like those can carry out photosynthesis because photosynthesis is achieved in organelles called chloroplasts which contain chlorophyll; this is what turn the sunlight, water, and CO2 into glucose. And it can be found in cells, they are not made of cells. Seaweed is basically a larger form of algae or euglena which is a bacteria, and the cells of this contain chloroplasts.
Seaweed originates from prokaryotes which includes all types of protists. Seaweed is found in many different varieties of algae but all belong to the kingdom of Protista.
Naked roasted seaweed -- not doctored seaweed with oils added -- is very, very low in calories. It is like eating naked lettuce.
Seaweed can be used in many different styles and types of dishes. Seaweed can be used in salads, soups, substitutions for other things in a recipe, sushi, risotto, rice dishes, mixed veggies and many more as well as unique creations can be made with seaweed.
It is formed from years in the seed proccess.
Detailed list: http://en.wikipedia.org/wiki/Seaweed#Uses
Carageenan is a seaweed that is used as a thickener in many food products, including ice cream.