deoxyribonucleic acid, desoxyribonucleic acid, DNA(noun) (biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information.
But even adults don't often know what a notochord is. A notochord is a primitive beginning to the backbone. It appears in embryos as a small flexible rod made from cells from the mesoderm, which is one of the three layers of cells of embryos. Notochords are only found in the phylum chordata, a group of animals that includes humans.
Chordates derive their name from one of their synapomorphies, or derived features indicating their common ancestry. This is the notochord, a semi-flexible rod running along the length of the animal.In those chordates which lack bone, muscles work against the notochord to move the animal.hordates derive their name from one of their synapomorphies, or derived features indicating their common ancestry. This is the notochord, a semi-flexible rod running along the length of the animal.