In one cubic meter of the ocean, photosynthetic plankton produce 80,000 calories of energy each year. how many calories of energy are available in the bodies of the creatures that eat that plankton?

The answer is  8,000 calories. This is because, in the transfer of energy from one trophic level to another, only 10% becomes available to be converted to biomass. The other 90% of lost into the environment as heat. This is why the energy pyramid tapers a you go up the pyramid.  

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.