Structures represented in the illustration below are found in the lower epidermis of a plant leaf. The illustration shows the response to a certain environmental condition. What are the structures that point T and Q and what would the response represented in the illustration most likely be caused by?

I think it's the third one: Letter Q points to the guard cell. Letter T points to the stomata and the response is most likely due to the humid tropical nature of the enviorment.

First, Mesopotamia was blessed with especially rich soil. Diverse elevations  (there are both high hills and low‐lying marshlands) and climatic variations in the region allowed for the evolution of many types of edible seeds and plants, as well as a variety of farm animals. California did not have it as easy as Mesopotamia did — it had several geographical disadvantages to conquer before its advantages could really shine.

Second, while the great city of Babylon was thriving in Mesopotamia in 3100 B.C., California remained rather insignificant as a trade or cultural center. It was inhabited by nomadic tribes who lived a hunter‐gatherer lifestyle.

Lastly, there was a speedy input of goods and knowledge via the waterways built across Mesopotamia. This was a distinct advantage of the area over competing regions, and allowed their economic and cultural life to flourish.