Mars was once similar to earth in that

a.) it had only one moon
b.) liquid water flowed on its surface
c.) it showed evidence of plate tectonics
d.) its atmosphere had a thin layer of carbon dioxide

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.