I believe it’s a chromosome.
A great amount of Antarctic animals feed on them. Whales, penguins, fish, birds, etc. They eat phytoplankton.
Nerve cells release neurotransmitters across gaps and secretion of proteins and wastes: it’s Exocytosis
The efficiency indicates the manner in which the inputs are used by the system. Being efficient means the system uses inputs in a `right' way. If the input-output ratio is adverse, we say that the system is inefficient though it produces the desired output.