Transpiration is fastest when humidity is low and temperature is ...

Question

Transpiration is fastest when humidity is low and temperature is high, but in some plants it seems to increase in response to light as well. During one 12-hour period when cloud cover and light intensity varied frequently, a scientist studying a certain crop plant recorded the data in the table (top right). (The transpiration rates are grams of water per square meter of leaf area per hour.) Do these data support the hypothesis that the plants transpire more when the light is more intense? If so, is the effect independent of temperature and humidity? Explain your answer. (Hint: Look for overall trends in each column, and then compare pairs of data within each column and between columns.)

Accepted Answer

Hi everyone. Here's our next question. It says. The loss of water from the aerial parts of plants is called transpiration. The rate of transpiration is controlled by various factors under which conditions will the rate of transpiration be the highest. So let's think about the different factors that affect transpiration and what will be the combination of factors that will make that rate the highest. We can look at our answer choices and we see that the three sort of areas that they're looking at are the intensity of the light. Light intensity, the temperature and the humidity. Mhm. And let's just kind of walk through this. So light intensity as light intensity increases while light causes the stomach to to open more. So the more intense the light, the more the stigmata will open and therefore the rate of transporation will go up with more open Samata. More water can evaporate out of the leaf temperature as the temperature goes up, while the higher heat is going to cause the water molecules to have more energy will move more and they'll be more likely to evaporate. So the temperature goes up, the rate of transporation will go up. Now humidity means the amount of moisture that of water vapor in the air. As humidity goes up, the air becomes more saturated with water, the more water vapor in the air surrounding the leaf, the less likely water molecules will be to evaporate into that saturated air. So as humidity goes up, the rate of transporation will go down. So therefore the conditions that will give us the highest rate of transpiration are intense light, high temperature and low humidity. With that in mind, let's look at our answer choices. Choice A. Says low light. So we can go ahead and eliminate that right away. We don't even look any further. That's not going to give us the highest rate of transportation. So eliminate Choice A. Choice B. Says intense light. So that's correct. High temperature and dry air. So those are our three conditions that are going to give us the highest rate of transpiration. So we can pick Choice B as our answer and we'll just look briefly at our other two choices. Choice C. Is low light. So again, eliminate that right away. Choice D. Has intense light. So that's correct. High temperature but then it has moist air and again, more humid air will cause a lower rate of transpiration. So that's why Choice D. Isn't correct. So under which conditions will the radio transporation be the highest choice be intense light, high temperature and dry air. See you in the next video

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