(noun) a division or contrast between two things that are or are represented as being opposed or entirely different.
(botany) repeated branching into two equal parts
This weak section of blood vessel is called an ANEURYSM. Aneurysm is defined as an excessive localized enlargement of an artery which is caused by the weakness of the artery wall. This weakness allows the artery to increase in size abnormally.
Evolution of a species reproductive it is race and hereditary