Parrots and Dogs are able to generate internal heat to maintain their body temperature in a coid environment. Parrots and Dogs are Endotherms. They generate most of the heat they need internally, when it's cold outside.
This is an organ that served a purpose in the distant ancestor of an organism, but is not longer pertinent in the presently existing, recently evolved, organisms.
After the macrophage fails the Helper T Cell stimulates the B cells (create antibodies) if pathogen is extracellular and Cytotoxic T Cells (killer T cells, release perforin) if pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
<span>Hope that's helpful.</span>
It is the dependent variable.
All of the noble gases which are helium neon argon krypton
