Video Transcript
Complete the following statements with “closed” or “open.” During the day, when there is available sunlight for photosynthesis, the stomata will
be blank. During the night, the stomata will be blank. In a very hot and dry environment, the stomata will be blank.
The stomata are tiny openings in a leaf’s surface that allow air to enter and
circulate among the leaf’s cells. This is important because it allows the cells to receive the carbon dioxide they need
to conduct photosynthesis. When there is plenty of water and sunlight for photosynthesis to occur, the stomata
will open. Water can also be evaporated out of the plant through these stomata. This is called transpiration.
The loss of water from the leaves during transpiration actually helps pull water up
from the roots to replace it and therefore aids in water circulation in the
plant. However, the plant needs to not lose water faster than it can be replaced. So when it is hot and dry, the stomata will close in order to not lose too much
water.
Now that we have a better idea of what causes stomata to open or close, let’s answer
our questions. When there is sunlight for photosynthesis, stomata will generally be open. When there is no sunlight, the stomata will close to conserve water. Especially in hot and dry environments, the stomata will remain closed to conserve
water.
During the day, when there is available sunlight for photosynthesis, the stomata will
be open. During the night, the stomata will be closed. In a very hot and dry environment, the stomata will be closed.
