A scientist has 400 grams of a radioactive substance with a half-life of one year. The amount of the substance that the scientist has after t years is represented by the expression 400(0.5)t. Which kind of expression is 400(0.5)t?

linear
quadratic
exponential growth
exponential decay

Which structure in the cardiovascular system connect arteries to veins?

The two main stages of cell division are called

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.