The stomata closes down at night when there is no sun and there's no photosynthesis. It also closes down when the air is dry and when it's hot so as to prevent excessive loss of water.
The Darwin's theory of evolution states that the organisms evolve through the process of the natural selection of the favorable genetic variations gradually over time. Through this process of the evolution, new species are developed over time. A single population may give rise to different species. These newly evolved species share similarities will each other as they have the same ancestor.
Hence, the given statement is 'true'.
The answer is Walter Hess
Hess manipulated the diancephalon of the brain of cats by inserting metal rods in the hypothalamus regions of the brain, where the diencephalon is located, and passing electrical current through the rods to the brain region. He noticed that the cats, among other complex behavioral changes, would curl up and sleep.