John covered the leaves of an outdoor plant with a clear, plastic bag. He then tied the bag shut around the stem of the plant. At the end of the day, he observed that the inside of the plastic bag was covered with moisture and was difficult to see through, as shown in the image below.

Question

What caused the inside of the plastic bag to become covered with moisture?
A.
Water from the air seeped into the bag and became trapped on the inner surface.
B.
The Sun condensed the water that was trapped in the air when the bag was tied on the plant.
C.
Water vapor transpired from the leaves of the plant and became trapped in the bag.
D.
The stem of the plant was unable to absorb water in the air because the bag was tied to it.

Answer 1

The correct answer is:

C. Water vapor transpired from the leaves of the plant and became trapped in the bag.

This happens because plants release water vapor as part of the transpiration process. When the plastic bag is sealed around the plant, the water vapor cannot escape and condenses on the inside surface of the bag, leading to the moisture observed.