HDWK Activity Chapter 8 Fig. 8.3 Questions and Answers | Latest Update | Graded A+

HDWK Activity Chapter 8 Fig. 8.3 Questions and Answers | Latest Update | Graded A+ **What were the alternative hypotheses the experiment was designed to test?** **Hypotheses 1: Water (H2O) is the source of the O2 released in photosynthesis.** **Hypothesis 2: Carbon dioxide (CO2) is the source of the O2 released in photosynthesis.** **Hypothesis 3: Both H2O and CO2 release O2 in photosynthesis.** **Hypothesis 4: O2 released during photosynthesis is derived from something other than H2O or CO2.** **What was the percentage of 16O2 in the test tubes at the start of the experiment?** **99.8%** **How did the amount of O2 in the test tubes change by the end of the experiment?** **The amount of O2 increased compared to the beginning of the experiment.** **At the end of the experiment, which test tube had a higher amount of 16O2?** **The test tube supplied with C18O2 had a higher amount of 16O2.** **At the end of the experiment, which test tube had a higher amount of 18O2?** **The test tube supplied with H218O had a higher amount of 18O2.** **Which hypothesis is supported by the experimental results regarding the source of O2 released in photosynthesis?** **Hypothesis 1: Water (H2O) is the source of the O2 released in photosynthesis.** **Why was the percentage of 18O in CO2 approximately 0.2% at the start of Experiment 1?** **About 0.2% of atmospheric oxygen atoms, including those in CO2, are naturally 18O.** **If the percentage of 18O in H2O was halved at the start of Experiment 1, what would be the predicted percentage of 18O in the O2 collected at the end?** **0.43%** **If the percentage of 18O in CO2 was halved at the start of Experiment 2, what would be the predicted percentage of 18O in O2 at the end?** **0.20%**