Robert Hooke. He first observed cells when looking at a piece of cork underneath a microscope.
When a commet containing single celled organisms, or the basic materials needed for single celled organisms to develope, hit the earth.
Single celled organisms were the first creatures.
It took many years of evolution for complex, multi-celled organisms to develop. Single celled organisms were the first that were around to be fossilized.
Anton Van Leeuwenhoek.
A single celled organism.
the first multi-celled and macroscopic organisms were called eukaryotes
Single-celled organisms, bacteria...algae
Single-celled organisms such as amoeba.
We do not really know what the first animal (or consumer) was but we think it was a single celled creature.
The single-celled organism that is most closely related to the first cell to exist on Earth is likely a type of archaea. Archaea are ancient single-celled microorganisms that are considered to be one of the earliest life forms on our planet. They share many genetic and biochemical similarities with the first cells that appeared on Earth.
archaebacteria are the type of bacteria which dates back to the first forms of life on earth. And its my guess that bacteria are unicellular whether unicellular or multicellular
microbes were the first inhabitants of earth. they are single-celled organisms; bacteria, fungi and protozoa. (: and Simple prokaryotes