The amount of water needed daily by plants for photosynthesis, cell growth, and cell maintenance is very small, and yet plants require large volumes of water in order to live. It is estimated that over 90 percent of the water absorbed by plants is lost into the air. Most of the water loss is due to evaporation from the plant through the small openings in leaves called stomata. This loss of water vapor from plants is referred to as transpiration.

The data represent the average transpiration value for twenty plants under each of the six experimental conditions. The room conditions were a temperature of 22°C, fluorescent lighting, and low humidity.

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3) Which of the following statements best explains the results associated with condition 5?
A) When a fan was added to heat and additional light, the rate of transpiration was slowed to the rate associated with room conditions, because the fan cooled the plants.
B) Additional heat and light and air movement caused the plants to lose so much water that after five minutes they wilted, thereby closing their stomata and preventing further water loss.
C) Additional heat resulted in such severe water loss that it could not be counteracted by air movement caused by the fan, and the plants died.
D) After five minutes the rate of transpiration gradually increased, because moisture was being brought up the stem more rapidly.



4) Which of the following hypotheses about the effects of high humidity is supported by the graph?
A) Plants will grow faster.
B) Plant tissues will contain a smaller volume of water.
C) Plants will close their stomata.
D) Evaporation will proceed more slowly.

What is condition 5?

We can't see the graph.

Plants wilted after 5 minutes.

Room Conditions 5 = + Additional Heat, + Additional Light, + Fan..

3.) I chose B

4.) I chose D

#3 I answered b.

The graph for 5 show + additional heat + additional light + fan.

Additional heat and light and air movement caused the plants to lose much water that after five minutes they wilted, thereby closing their stomata and preventing futher water loss.

To answer these questions, you need to analyze the information presented in the passage and interpret the data in the graph. Let's go through each question and find the correct answer:

3) The passage mentions that the room conditions had low humidity. We need to find the statement that explains the results associated with condition 5. Looking at the options:
A) This statement suggests that the addition of a fan slowed down the rate of transpiration because it cooled the plants. However, the passage does not mention anything about cooling effects.
B) This statement suggests that the plants lost so much water due to additional heat, light, and air movement that they wilted and closed their stomata. This seems plausible because the passage states that transpiration is the loss of water vapor from plants.
C) This statement suggests that the additional heat resulted in severe water loss that could not be counteracted by air movement, leading to the death of the plants. The passage does not mention any information about the plants dying.
D) This statement suggests that the rate of transpiration gradually increased after five minutes due to moisture being brought up the stem more rapidly. However, the passage does not provide any information about moisture being transported more rapidly.

The best explanation based on the given information is B. Additional heat, light, and air movement caused the plants to lose so much water that they wilted, closing their stomata and preventing further water loss.

4) The question asks about the effects of high humidity. Looking at the options:
A) This option suggests that plants grow faster under high humidity. However, the passage and the graph do not provide any information about the growth rate of plants.
B) This option suggests that plant tissues will contain a smaller volume of water under high humidity. This aligns with the fact that plants lose water through transpiration, and high humidity would potentially decrease the rate of transpiration.
C) This option suggests that plants will close their stomata under high humidity. This aligns with the fact that stomata openings are responsible for water loss through transpiration, and high humidity could potentially reduce the need for transpiration.
D) This option suggests that evaporation will proceed more slowly under high humidity. This aligns with the fact that evaporation rates generally decrease with higher levels of humidity.

Based on the given information, the hypothesis supported by the graph is C. Plants will close their stomata under high humidity.

Therefore, the answers to the questions are:
3) B) Additional heat and light and air movement caused the plants to lose so much water that after five minutes they wilted, thereby closing their stomata and preventing further water loss.
4) C) Plants will close their stomata.