What tissue forms the model for endochondral ossification?

Which of the following is a limitation of a clinical trial? a.)amount of random assignments b.)hospital cost c.)number of test tubes d.)amount of peer review

The earths core is made up mainly of what 2 substances? 2. like an egg, earth has a core, a layer surrounding the core, and a thin, hard outer layer. which layers of the earth match the layers of an egg?

When the grand canyon formed many small mammal population were divided. some members of the population were on one side and others are on the other, therefore, they were no able to mate with one another. over time this separation and inability to mate with one another led to the emergence of new species. this type of speciation is called a) sympatric speciation. b) allopatric speciation. c) parapetric speciation. d) peripatric speciation.