When doing medical research with human subjects, which four limitations are unavoidable? It’s often impossible to repeat trials on the same subjects.
Subjects may report an inaccurate medical history.
It can be difficult to control all possible variables.
It’s impossible to come up with testable scientific questions for human subjects.
There are ethical or privacy concerns to consider.

Physical characteristics of down syndrome

4. multiple crosses were made between true-breeding lines of black and yellow labrador retrievers. all the f1 progeny were black. when these progeny were intercrossed, they produced an f2 consisting of 91 black, 39 yellow and 30 chocolate. a. propose an explanation for the inheritance of coat color in labradors. b. propose a biochemical pathway for coat color determination and indicate how the relevant genes control coat coloration.

What will a hypothesis become if supported by repeated expermentation