Reduction 

Using fewer animals when testing

Replacement 

Using something else to do the same kind of testing.

Refinement

Changing experiment to help the animals 

Sister Group

Group adjacent to the group of focus. 

Monophyletic

A group made up of a common ancestor and all its decendants 

Paraphyletic    

A Group that contains most recent common anscestors but not all acendants

Polyphyletic 

Traits its members have in common but evolved seperately in different places in the phylogentic tree.  

Binary Fission

Spliting into two daughter cells

Mutiple Fission

Asexual reproduction involving a major split. (schizogony) 

Anarobic

Without Oxygen 

Aerobic    

With oxygen

Blastocoel

Cavity in the blastula stage 

Blastopore 

Opening at the end 

Homologous Trait 

Analogous Trait 

A trait that is morphologically and functionally similar to another, but which arose from a different ancestral condition.