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 feature uniting all chordates (all vertebrates and some invertebrates) is that at some stage in their lives, all have a flexible supporting rod, a notochord, that runs through the length of their bodies.ifferences in Physical Characteristics. Vertebrates have a skeletal structure with a spinal column or backbone. Invertebrates have no backbone, while vertebrates have a well-developed internal skeleton of cartilage and bone and a highly developed brain that is enclosed by a skull.