He diagram below represents a stack of rock layers. Examine the diagram, and answer the question that follows. What do these layers and their fossils suggest about Earth's history?
A.
Lifeforms on Earth have been the same over time.
B.
No lifeforms were present when these layers formed.
C.
There have been changes in Earth's lifeforms over time.
D.
Only one kind of lifeform lived where these layers formed.

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.