Photovoltaic cells are used in solar lighting, often used to light up a sidewalk or garden. The lights gather energy from the sun during daylight hours in order to shine at night. Which of the following is the main element used to produce electricity in a photovoltaic cell? A) gaseous hydrogen
B) solid silicon
C) Liquid water

In the example of adrenaline signaling, which steps represent an amplification of the signal? question 1 choiceschoice a., activated receptor activates g proteins, g protein binding by gtp, cyclic amp activation of protein kinase achoice b., activated receptor activates g proteins, activated adenylyl cyclase produces camp, active protein kinase a phosphorylates target proteinschoice c., receptor signal binding, activated receptor activates g proteins, activated adenylyl cyclase producing campchoice d., receptor signal binding, activated adenylyl cyclase producing camp, active protein kinase a phosphorylating target proteins