Nina is learning about plants in school. Her teacher gives her group a stack of cards that list things that plants might need to make their own food. Written on the cards are the words “water,” “soil,” “sunlight,” and “air.” One card does not belong. Which of the cards should Nina’s group take out of the pile?

A) air
B) soil
C) sunlight
D) water

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.