A new trait
a derived trait
cladogram
A cladogram will show the genus and family of organisms and the offshoots of these said organisms including those that no longer exist in the present day.
A blood clot, also called a thrombus, in the anterior interventricular branch causes sudden death. This branch supplies the majority of blood to the walls of both ventricles. The presence of a thrombus can block the bloodflow to heart muscle cells, causing instant death.
Is it what? Is it interesting? Is it useful? Is it purple? Is it... oh, never mind. Your "question" isn't actually a question - you need to add the word "What" at the beginning. Like this:"What is the branch of biology that deals with the grouping and naming of living things?"...But the answer to your non-question is "taxonomy".
Ethics is a branch of philosophy, not a branch of science (although scientists can still strive to be ethical).