Mrs. Wright (who is always right, just ask her), is caring for her son's prize tomato plants while he attends a Tomatologist Conference.
She brings them into the house due to a pending ice storm and places them in a dark room. She provides plenty of water and soil nutrients, but does not turn on the lights to conserve energy.
Which of the following is most likely to occur first?
a
Calvin cycle will continue fas long as the products from the light dependent cycle and CO2 are available.
b
Fermentation will begin in the chloroplasts of the leaf cells.
c
Light dependent cycle will continue at the same rate with adequate water and nutrients.
d
Photosynthesis will end abruptly, as Mrs. Wade is a plant murderer.
c
The correct answer is c) The light dependent cycle will continue at the same rate with adequate water and nutrients.
Photosynthesis consists of two main stages, the light-dependent reactions and the Calvin cycle. The light-dependent reactions occur in the thylakoid membrane of chloroplasts and require light energy to convert water into oxygen and ATP. This stage is not directly affected by the absence of light, so it will continue as long as there is adequate water and nutrients.
The Calvin cycle, also known as the dark reactions or light-independent reactions, occurs in the stroma of the chloroplasts and uses ATP and carbon dioxide to produce glucose. This stage depends on the products of the light-dependent reactions and carbon dioxide availability, so it may be affected if the plants are kept in the dark for a prolonged period of time. However, since Mrs. Wright provides plenty of water and soil nutrients, it is likely that the light-dependent cycle will continue at the same rate.
To determine which of the given options is most likely to occur first, we need to understand the processes involved in photosynthesis and how they can be affected by the conditions provided by Mrs. Wright.
Photosynthesis is the process by which plants convert light energy into chemical energy in the form of glucose. It consists of two stages: the light-dependent reactions and the Calvin cycle (also known as the light-independent or dark reactions).
During the light-dependent reactions, light energy is captured by chlorophyll in the chloroplasts and used to produce ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate) molecules. These molecules are necessary for the Calvin cycle to occur. The light-dependent reactions require light to happen and take place in the thylakoid membranes of the chloroplasts.
The Calvin cycle, which is the second stage of photosynthesis, uses the ATP and NADPH produced in the light-dependent reactions, as well as CO2 from the atmosphere, to synthesize glucose. The Calvin cycle does not require light and can occur in the absence of light as long as the necessary components (products from the light-dependent reactions and CO2) are available.
Given the conditions provided by Mrs. Wright (dark room, adequate water, and nutrients), we can eliminate option d ("Photosynthesis will end abruptly, as Mrs. Wright is a plant murderer") because photosynthesis can still occur in the absence of light as long as the necessary components are available.
Option a ("Calvin cycle will continue as long as the products from the light-dependent cycle and CO2 are available") is a correct statement. The Calvin cycle can continue to occur in the dark as long as ATP and NADPH from the light-dependent reactions and CO2 are available.
Option b ("Fermentation will begin in the chloroplasts of the leaf cells") is incorrect. Fermentation is an anaerobic process that occurs in the absence of oxygen, and it is not directly related to photosynthesis.
Option c ("Light-dependent cycle will continue at the same rate with adequate water and nutrients") is incorrect. The light-dependent reactions cannot occur in the absence of light. Therefore, the light-dependent cycle will not continue at the same rate in the dark.
Therefore, the most likely occurrence would be that the Calvin cycle continues as long as the products from the light-dependent cycle and CO2 are available, making option a the correct answer.
Note: It is important to note that while photosynthesis can continue in the absence of light, it is typically less efficient in the dark compared to when light energy is available.