AP BIOLOGY

PLANTS

TRANSPORT IN PLANTS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Colder temperatures cause stomata to remain closed. Based on this information, if a plant were grown below 21oC would you expect transpiration rates to
A
increase.
B
decrease.
C
stay the same.
D
you would not be able to determine a difference in rate.
Explanation: 

Detailed explanation-1: -At low temperatures, plants dehydrate because of restricted water uptake. Under these conditions, rapid stomatal closure (i.e., hours after first being exposed to cold stress) limits water loss. This mechanism occurs in cold-tolerant, but not cold-sensitive species (Wilkinson et al., 2001).

Detailed explanation-2: -Increased humidity has a reduces transpiration. The lower the humidity the easier it is for the plant to release water. The type of plant is also a factor in how much a plant will transpire. For example plants grow in arid hot areas such as the desert will transpire less as they aim to conserve water.

Detailed explanation-3: -The loss of water as vapor from plants at their surfaces, primarily through stomata. rates increase; when they are closed, transpiration rates decrease. A region of still air near the surface of a leaf through which water must diffuse en route to the atmosphere.

Detailed explanation-4: -Plants transpire more rapidly in the light than in the dark. This is largely because light stimulates the opening of the stomata (mechanism). Light also speeds up transpiration by warming the leaf. Plants transpire more rapidly at higher temperatures because water evaporates more rapidly as the temperature rises.

There is 1 question to complete.