Â· just now. Report Abuse. It takes a good 6-8 weeks for a break to heal properly. A compound fracture, spiral fracture or complete break would take closer to 8 weeks. A greenstick fracture could heal in as little as 4-6.eport Abuse. Most broken bones begin to heal within 48 hours however depending on the type and severity of the break it could take anywhere from 4 to 8 weeks to completely heal.
Science Main Index. Animals with an internal skeleton made of bone are called vertebrates. Vertebrates include fish, amphibians, reptiles, birds, mammals, primates, rodents and marsupials. Although vertebrates represent only a very small percentage of all animals, their size and mobility often allow them to dominate their environment.
The Chordates. Chordates have an internal flexible rod, the first stage in the evolution of a truly internal skeleton. 48.2 Nonvertebrate chordates have a notochord but. no backbone. The Nonvertebrate Chordates. Lancelets are thought. to resemble the ancestors of vertebrates. 48.3 The vertebrates have an interior framework of.