What part of the chromosome is thought to be the location where cells lose their ability to replicate?

Which of these is NOT a basic condition that must be met before a cause-and-effect relationship between a risk factor and a health outcome can be inferred?

A) The evidence must be consistent. B) The relationship need not make sense. C) There must be a dose-response relationship. D) The alleged cause must have been in place before the health outcome appeared.

Gender ________ is the tendency for boys and girls to play in same-sex groups

a. schema b. identity c. segregation d. control