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.%0D%0A%0D%0AHere are her results:%0D%0A%0D%0ADay 2: slight mark where the paper covered the leaf; it is a lighter green than the rest of the leaf.%0D%0A%0D%0ADay 4: yellow circle where the construction paper was.%0D%0A%0D%0ADay 7: almost white circle where the paper covered the leaf.%0D%0A%0D%0AUsing your knowledge of photosynthesis, which answer choice explains her results the best?%0D%0A%0D%0A(1 point)%0D%0AResponses%0D%0A%0D%0AThe 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.%0D%0A%0D%0AThe 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.%0D%0A%0D%0AThe 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.%0D%0A%0D%0AThe 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.%0D%0A%0D%0AThe 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.%0D%0A%0D%0AThe 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.%0D%0A%0D%0AThe 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.%0D%0A%0D%0AThe 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 most appropriate answer choice that explains the student's results is:
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 answer choice that explains the student's results the best is:
"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 answer choice that explains the student's results is:
"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 understand why this is the correct answer, we need to understand the process of photosynthesis. Photosynthesis is the process by which plants convert sunlight into energy (in the form of sugars) to fuel their growth and survival. It occurs in specialized structures within plant cells called chloroplasts, which contain a pigment called chlorophyll. Chlorophyll absorbs sunlight and uses its energy to convert carbon dioxide and water into glucose (sugar) and oxygen.
In this experiment, the student placed construction paper circles on different leaves of the plant, blocking the sunlight from reaching the covered part of the leaves. As a result, those areas didn't receive any light energy necessary for photosynthesis to occur. Without light, the chlorophyll in those cells couldn't absorb sunlight and therefore couldn't convert carbon dioxide and water into glucose and oxygen. This explains why, on Day 2, there was only a slight mark where the paper covered the leaf, as the leaf cells were still able to perform some cellular respiration using stored energy. On Day 4, the yellow circle formed because the blocked area's chlorophyll had degraded due to lack of light. Finally, on Day 7, the almost white circle formed as the chlorophyll had completely lost its function.
Therefore, the best explanation for the student's results is that without light, photosynthesis couldn't occur in the covered parts of the leaves, resulting in the observed changes in color.