Primitive in Biological Definition

Origin of life

... Shaw (1973) commented: "If there ever was a primitive soup, then we would expect to find at least ... a "naked-gene" and postulate the emergence of a primitive metabolism which could provide an environment for ... in 1924 with Alexander Oparin 's notion of primitive self-replicating vesicles which predated the ...

Protein

... parce quil parat tre la substance primitive ou principale de la nutrition animale.» translated as: "I propose ... because it appears to be the primitive or principle substance of animal nutrition." Investigation of ...

Animal

... certain. Platyzoa The Platyzoa include the phylum Platyhelminthes , the flatworms. These were originally considered some of the most primitive Bilateria, but it now appears they developed from more complex ancestors. A number of parasites are included in this group, such as the flukes and ...

Brain

... . Vertebrates are characterized by increasing complexity in the cerebral cortex as one moves up the phylogenetic and evolutionary tree . primitive vertebrates, like fish, reptiles, and amphibians have cortices with less than six layers of neurons, a structure known as allocortex (Martin, 1996). ...

Cryptozoology

... summarily dismissed in the same way. There are several animals cited as examples for continuing cryptozoological efforts: The coelacanth , a primitive fish , a " living fossil " believed to have been extinct for 65 million years, was caught in a fishing net in 1938 off the coast of Africa . ...

Fungus

... on the inside; some soil-dwelling fungi actually trap roundworms and other small animals. Most chytrids, which are generally considered the most primitive group of fungi, do not form hyphae and instead grow directly from spores into multinucleate sporangia . A few other fungi have reverted from a ...

Glucose

... such as fructose , is so widely used. Glucose can form from formaldehyde under abiotic conditions, so it may well have been available to primitive biochemical systems. Probably more important to advanced life is the low tendency of glucose, by comparison to other hexose sugars, to ...

Animal

... certain. Platyzoa The Platyzoa include the phylum Platyhelminthes , the flatworms. These were originally considered some of the most primitive Bilateria, but it now appears they developed from more complex ancestors. A number of parasites are included in this group, such as the flukes and ...

Nervous system

... possess a network of nerves that operates like a more conventional nervous system, but lack a brain. Annelid worms and tunicates have a primitive brain called a ganglionic mass, which is a bundle of several nerves. Based in part on commonalities in embryonic development among all chordates ...

Paleontology

... at the fossils contained in a rock remains one of the fastest and most accurate means of telling how old that rock is. Fossils were known by primitive man and were sometimes identified correctly as the remains of ancient lifeforms. The organized study of paleontology dates from the late 18th ...

Plant

... transport water throughout the organism. In many the sporophyte acts as a separate individual, while the gametophyte remains small. The first primitive seed plants, Pteridosperms (seed ferns) and Cordaites, both groups now extinct, appeared in the late Devonian and diversified through the ...

Plant

... transport water throughout the organism. In many the sporophyte acts as a separate individual, while the gametophyte remains small. The first primitive seed plants, Pteridosperms (seed ferns) and Cordaites, both groups now extinct, appeared in the late Devonian and diversified through the ...