What is the difference between protozoans and methazoans?

The difference between protozoans and methazoans is that Protozoans are unicellular organisms, while methazoans are multicellular. The definition of methazoans is relatively clear for most examples, as well as protozoans, although both have fuzzy edges. The term "Protozoa" (which means "first animals") concerns any animal unicellular organism, while unicellular organisms similar to plants are called algae. However, there are organisms that are blurring these two: for example, the eyelashes have chloroplastics, but can also move and feed on organic matter. Many seemingly unicellular organisms are also arranged into a fiber of similar or spherical colonies such as cyanobacteria or chroophyte Volvox .

The term "Protozoan" essentially covers any unicellular organism, which is not an animal, plant, bacteria or fungi. According to the definition, each member of Kingdom Animallia is multicellia and another name for the kingdom is actually metazoa. SupremeThe onar photosynthetic unicellular non -organisms are not protozoans partly because the extension -zoa means an animal, and it is obviously not at all similar to an animal. Protozoans are always movable because there are no protozoans that can survive by a stationary filter, unlike numerous animals such as mushrooms, corals, barnacles, limpets and brachiopods that do so.

Protozoans ranges from 10-50 microns (million meters), but several species are up to 1 mm. Metazoans ranges from about 50 microns, as in the smallest braopepods, through the blue whale (34 m or 111 ft), the lion's jellyfish (36.5 m or 120 feet) and the Worm booting (55 m or 180 ft). The extinct dinosaur ampicoeliad fragillimus could be 60 m (197 ft) or longer. As we can see, the largest metazoans may be up to a million times larger than a typical protozoan, although most methazoans have a small size, less than mm in length. Macroscopic Metazoans, such as humans, are in a minority.

It is assumed that Metazoans developed from protozoans about 600 million years ago, although the evidence of molecular systematics suggests earlier. Because the first metazoan animals had to be very small and made up only of soft tissue, they should not be fossilized too well, although one of the first known metazoan fossils, a small spherical animal called Vernanimalcula Guizhouena, was only 0.1 to 0.2 mm in size, and approximately a/p>