The final electron acceptor of cellular respiration is

The final electron acceptor is indeed oxygen but let me explain it better: This process occur during cell metabolism. The thing is that the potential of NADH and FADH2 is converted into more ATP, which is the Adenosine triphosphate, through an electron chain that contains oxygen and that is why is called the terminal electron acceptor. 

What have scientists learned about plant behavior by studying the dodder plant

Your answer is going to be b.