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.
These are called tube feet. By varying the internal water pressure, the echinoderm can extend and contract its tube feet for locomotion, food collection and respiration. Characteristic of all echinoderms is the presence of an internal skeleton covered with spines and skin.The skeleton varies with the type of echinoderms. In sea stars and brittle stars, the skeleton consists of multitudes of small calcareous plates called âossiclesâ that move with one another, forming flexible joints.chinoderms are characterized by their radial symmetry, water vascular system and internal skeleton. The most striking feature of all echinoderms is their pentamerous radial symmetry.