Thus, the emergence of metabolic pathways allowed primitive organisms to become increasingly less dependent on exogenous sources of organic compounds.
If two planets independently evolved primitive organisms, then it seems more likely that this type of life can be found on many planets throughout the universe.
Slime mold, any of about 500 species of primitive organisms containing true nuclei and resembling both protozoan protists and fungi.
The Precambrian also includes the first appearance of life on Earth, which is represented by rocks with mainly bacteria, algae, and similar primitive organisms.
Professor Barabasi makes that prediction partly because he and his researchers mapped out the interactions of 43 primitive organisms and found they took the form of a network with rules.
Primitive organisms, such as blue-green algae (or cyanobacteria), cause carbon dioxide and water to react by photosynthesis to produce carbohydrates, which they need for growth, repair, and other vital functions, and this reaction releases free oxygen.
Most of those luminous primitive organisms subsequently developed systems of using oxygen, but they have retained the luminescent capability as parts of related metabolic pathways or for some survival value that luminescence may confer on the organism.
The earliest primitive organisms produced free oxygen as a by-product, and in the absence of oxygen-mediating enzymes it was harmful to their living cells and had to be removed.
Herbert Croly, who co-founded The New Republic, in 1914, liked to say that the Republicans and Democrats were (to borrow a paraphrase from Walter Lippmann's recollection of Croly) like primitive organisms that can't easily be killed: if their heads and tentacles are lopped off, they grow new ones.
Such similarities in neurochemistry that allow caffeine to affect mammalian and insect brains in similar ways may seem surprising, but insects like fruit flies and the nervous systems of even more primitive organisms like nematodes have been used to study learning at the level of individual cells and the chemistry that changes their activities.
Sponges are one of the most primitive organisms that lack definitive tissue grade organisation.
