A student was conducting a scientific experiment with a plant. She cut out three 1-inch circles from construction paper and attached each circle to a different leaf of the plant. Finally, she set the plant in front of a sunny window with good air flow and left it there. She made sure that the plant was given enough water during her experiment. After 2 days, she removed one of the circles; after 4 days, she removed another circle; and at the end of the week, she removed the last circle
.Here are her results
:Day 2: slight mark where the paper covered the leaf; it is a lighter green than the rest of the leaf.
Day 4: yellow circle where the construction paper was.
Day 7: almost white circle where the paper covered the leaf
.Using your knowledge of photosynthesis, which answer choice explains her results the best?
(1 point)Responses
1. The part of the leaves that were covered with paper didn't allow for water to be absorbed. Without water, photosynthesis was unable to take place because the phloem was not able to bring the needed water molecules to the roots
2.The part of the leaves that were covered with paper didn't get any light. Without light, cellular respiration was unable to take place because the mitochondria within the leaf cells were unable to absorb the ATP energy needed for the chemical reaction.
3.The part of the leaves that were covered with paper didn't get any light. Without light, photosynthesis was unable to take place because the chlorophyll within the leaf cells were unable to absorb the sunlight energy needed for the chemical reaction.
4. The part of the leaves that were covered with paper didn't allow for gas exchange through the leaf's stomata. Without oxygen, photosynthesis was unable to take place because the needed reactant of oxygen was missing
The best answer choice that explains the student's results is:
3. The part of the leaves that were covered with paper didn't get any light. Without light, photosynthesis was unable to take place because the chlorophyll within the leaf cells were unable to absorb the sunlight energy needed for the chemical reaction.
The best explanation for the student's results is option 3: The part of the leaves that were covered with paper didn't get any light. Without light, photosynthesis was unable to take place because the chlorophyll within the leaf cells were unable to absorb the sunlight energy needed for the chemical reaction.
To determine the best answer choice that explains the student's results, we need to understand the process of photosynthesis and how it is affected by the experiment.
Photosynthesis is the process by which plants convert sunlight, water, and carbon dioxide into glucose (sugar) and oxygen. This process occurs in the chloroplasts of plant cells, specifically in specialized structures called chlorophyll. Chlorophyll absorbs energy from sunlight and uses it to produce glucose.
Looking at the experiment and the results, we can rule out option 1 because the water absorption and transportation through the phloem (vessels in the plant that transport water and nutrients) are not directly related to photosynthesis. The student made sure the plant was given enough water during the experiment.
Option 2 can also be ruled out because cellular respiration, which is the process by which cells produce energy from glucose, is not directly related to the experiment. The purpose of the experiment is to observe the effects of light on photosynthesis.
Option 3 is the best answer choice. The part of the leaves that were covered with paper didn't receive any light. Without light, photosynthesis cannot occur because the chlorophyll within the leaf cells is unable to absorb the sunlight energy needed for the chemical reaction. This explains the observed results of the experiment, such as the lighter green mark on the leaf on day 2, the yellow circle on day 4, and the almost white circle on day 7. These changes in color suggest a lack of chlorophyll activity due to the absence of light.
Option 4 is not the best answer choice because while gas exchange through the leaf's stomata is important for photosynthesis, it primarily involves the exchange of carbon dioxide and oxygen. The absence of gas exchange would affect the availability of carbon dioxide, but it wouldn't directly explain the changes in color observed in the experiment.
Therefore, the correct answer is option 3: The part of the leaves that were covered with paper didn't get any light. Without light, photosynthesis was unable to take place because the chlorophyll within the leaf cells were unable to absorb the sunlight energy needed for the chemical reaction.