Question

If the input water is labeled with a radioactive isotope of oxygen, 18O, then the oxygen gas released as the reaction proceeds is also labeled with 18O. Which of the following is the most likely explanation (A) During the light reactions of photosynthesis, water is split, the
hydrogen atoms combine with the CO2, and oxygen gas is released.
(B) During the light reactions of photosynthesis, water is split, removing
electrons and protons, and oxygen gas is released.
(C) During the Calvin cycle, water is split, regenerating NADPH from
NADP+, and oxygen gas is released.
(D) During the Calvin cycle, water is split, the hydrogen atoms are added
to intermediates of sugar synthesis, and oxygen gas is released.

Answer 1

Answer:

b. During the light reactions of photosynthesis, water is split, removing electrons and hydrogen ions, and oxygen gas is released.

Explanation:

During the light reactions of photosynthesis the oxygen present in the water is released.

As we know, photosynthesis happens when chlorophyll absorbs sunlight. At that time, the water and carbon dioxide captured by the plant are converted into a glucose molecule. During this process, the water is "broken", losing electrons and hydrogen ions. In this case, the oxygen ends up being thrown out of the reaction and dissolved in the environment. You can observe this process through the equation below:

6 CO2 + 12 H2O ----> C6H12O6 + 6 O2 + 6 H2O

Answer 2

Answer:

The appropriate explaining for the release of labelled oxygen in the reaction is that, during the Calvin cycle, water is split, the hydrogen atoms are added  to intermediates of sugar synthesis, and oxygen gas is released.

Explanation:

Photosynthesis is the reaction of plants for production of food i.e. sugar. The reaction of photosynthesis is:

$\rm 6\;CO_2\;+\;6\;H_2O\;+\;Chlorophyll\;+\;Enerygy\;\rightarrow\;C_6H_1_2O_6\;+\;6\;O_2$

Since the water up taken by the plants has radio labelled oxygen, $\rm ^1^8O$. During the Calvin cycle of the plant respiration, the water molecule splits into hydrogen and oxygen and contributes in the formation of Sugar along with release of oxygen. The oxygen molecules of $\rm CO_2$ are splits to form sugar moiety. The water splits and releases oxygen. Since the released oxygen is part of water molecule. The radio-labelled water with $\rm ^1^8O$ will release radio-labelled oxygen $\rm ^1^8O$.

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https://brainly.com/question/3199721?referrer=searchResults