1.
Which of the following is true concerning the C4 pathway?
Correct Answer
B. It feeds into the C3 pathway.
Explanation
The C4 pathway is a biochemical process in plants that allows them to efficiently fix carbon dioxide and minimize water loss. It involves the production of large amounts of carbohydrates, but this statement is not true concerning the C4 pathway. The correct answer is that it feeds into the C3 pathway. In the C4 pathway, carbon dioxide is first fixed into a four-carbon compound, which is then transported to the mesophyll cells where it releases carbon dioxide to be used in the C3 pathway. This allows plants to overcome the limitations of the C3 pathway and enhance their photosynthetic efficiency.
2.
Which of the following would NOT be true of CAM plants?
Correct Answer
A. They fix carbon only once.
Explanation
CAM plants, or Crassulacean Acid Metabolism plants, have a unique adaptation to arid environments. They fix carbon dioxide at night by opening their stomata and storing it as organic acids. During the day, when the stomata are closed to prevent water loss, they use these stored acids to perform photosynthesis. This allows them to conserve water and minimize water loss. Therefore, the statement "They fix carbon only once" is not true for CAM plants, as they fix carbon dioxide twice, once at night and once during the day.
3.
ATP is
Correct Answer
A. The energy currency of a cell.
Explanation
ATP (adenosine triphosphate) is known as the energy currency of a cell because it is the primary molecule used by cells to store and transfer energy. It is produced through cellular respiration, where ADP (adenosine diphosphate) is converted into ATP by adding a phosphate group. When energy is needed, ATP is broken down into ADP, releasing the stored energy that can be used for various cellular processes. Therefore, ATP serves as a crucial molecule in providing energy for cellular activities, making it the correct answer.
4.
ATP
Correct Answer
E. All of these.
Explanation
ATP can be produced by photosynthesis, which is the process by which plants convert sunlight into chemical energy. It is also produced in the degradation of organic compounds such as glucose, which occurs during cellular respiration. ATP is generated in anaerobic respiration, which is a type of respiration that occurs in the absence of oxygen. Finally, ATP is formed in aerobic respiration, which is a type of respiration that occurs in the presence of oxygen. Therefore, all of these processes contribute to the production of ATP.
5.
Plant cells are capable of
Correct Answer
E. All of these.
Explanation
Plant cells are capable of all of these processes. Photosynthesis is the process by which plants convert sunlight, water, and carbon dioxide into glucose and oxygen. ATP production is the process by which plants generate energy to carry out various cellular activities. Glucose breakdown is the process by which plants break down glucose to release energy. Aerobic respiration is the process by which plants use oxygen to convert glucose into carbon dioxide and water, releasing energy in the process. Therefore, plant cells are capable of all of these processes.
6.
When molecules are broken apart in respiration,
Correct Answer
C. The energy released in respiration is channeled into molecules of ATP.
Explanation
When molecules are broken apart in respiration, the energy released is channeled into molecules of ATP. ATP (adenosine triphosphate) is a molecule that stores and releases energy in cells. This process allows cells to use the energy from respiration to power various biological reactions and processes.
7.
Cellular respiration
Correct Answer
A. Evolved to enable living organisms to utilize energy stored in glucose.
Explanation
Cellular respiration is a process that evolved in living organisms to enable them to utilize the energy stored in glucose. Glucose is broken down through a series of biochemical reactions, releasing energy in the form of ATP. This energy is essential for various cellular activities and is used by all living organisms to carry out their functions. Therefore, the evolution of cellular respiration allowed organisms to efficiently extract energy from glucose and utilize it for survival and growth.
8.
Aerobic organisms use _____ as the final electron acceptor in aerobic cellular respiration.
Correct Answer
C. Oxygen
Explanation
Aerobic organisms use oxygen as the final electron acceptor in aerobic cellular respiration. During this process, glucose is broken down in the presence of oxygen to produce energy in the form of ATP. Oxygen acts as the final electron acceptor in the electron transport chain, which is the last step of cellular respiration. This allows for the efficient production of ATP molecules, providing energy for various cellular activities.
9.
Which of the following liberates the most energy in the form of ATP?
Correct Answer
A. Aerobic respiration
Explanation
Aerobic respiration is the process by which cells convert glucose into ATP, the energy currency of the cell. It occurs in the presence of oxygen and is the most efficient way to produce ATP, liberating the most energy. Anaerobic respiration, alcoholic fermentation, and lactate fermentation also produce ATP, but they are less efficient and liberate less energy compared to aerobic respiration. Therefore, aerobic respiration is the process that liberates the most energy in the form of ATP.
10.
During the Krebs cycle,
Correct Answer
E. All of these.
Explanation
During the Krebs cycle, multiple processes occur simultaneously. Substrate-level phosphorylation refers to the production of ATP by transferring a phosphate group from a substrate molecule to ADP. Oxaloacetate is constantly regenerated to ensure the continuous flow of the cycle. Electrons and H+ ions are transferred to coenzymes NAD+ and FAD, which are crucial for the electron transport chain. Lastly, carbon dioxide molecules are formed as byproducts of the cycle. Therefore, all of these processes occur during the Krebs cycle.
11.
In respiration, the greatest number of ATP molecules is produced in
Correct Answer
D. Electron transfer pHospHorylation.
Explanation
Electron transfer phosphorylation, also known as oxidative phosphorylation, occurs in the mitochondria and is the final step in cellular respiration. It involves the transfer of electrons from electron carriers to the electron transport chain, which generates a proton gradient across the inner mitochondrial membrane. This proton gradient is then used by ATP synthase to produce ATP molecules. This process produces the greatest number of ATP molecules compared to other steps in respiration such as glycolysis, acetyl-CoA formation, anaerobic electron transfer, and the Krebs cycle.