Just as the Pleistocene was ending and Earth was warming, an event called the Younger Dryas plunged Earth back into one thousand years of cold temperatures. What is one leading hypothesis for the cause? Question 19 options:

glaciation of Antarctica

"nuclear winter" due to asteroid impact over Greenland

glaciation of the Andes and Himalaya

burial of organic carbon decreasing atmospheric CO2

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.