1.
The process by which plants use sunlight to make glucose is called ___.
Correct Answer
A. pHotosynthesis
Explanation
Photosynthesis is the correct answer because it is the process by which plants use sunlight to convert carbon dioxide and water into glucose and oxygen. This process occurs in the chloroplasts of plant cells and is essential for the plant's survival as it provides energy for growth and development. Cellular respiration, the cell cycle, and mitosis are not related to the process of using sunlight to make glucose.
2.
Where do the hydrogen ions for the photosystems of the light-dependent reactions come from?
Correct Answer
D. Water
Explanation
The hydrogen ions for the photosystems of the light-dependent reactions come from water. During photosynthesis, water molecules are split by light energy, releasing oxygen and protons (hydrogen ions). These protons are then used in the photosystems to generate ATP and NADPH, which are essential for the synthesis of sugars. Therefore, water serves as the source of hydrogen ions in the light-dependent reactions of photosynthesis.
3.
Which phrase best describes the electron transport chain in photosynthesis?
Correct Answer
C. A series of proteins located in the thylakoid membrane
Explanation
The electron transport chain in photosynthesis is a series of proteins located in the thylakoid membrane. This chain is responsible for transferring electrons from photosystem II to photosystem I, generating a proton gradient across the membrane, and ultimately producing ATP and NADPH, which are used in the Calvin cycle to produce glucose. The thylakoid membrane is where the light-dependent reactions of photosynthesis take place, and the proteins in the electron transport chain play a crucial role in this process.
4.
In the light-independent reactions of photosynthesis,
Correct Answer
A. Carbon dioxide enters the Calvin cycle and sugars are made.
Explanation
In the light-independent reactions of photosynthesis, carbon dioxide enters the Calvin cycle and sugars are made. This is because the Calvin cycle is responsible for converting carbon dioxide into glucose, which is a sugar molecule. This process occurs in the stroma of the chloroplasts and requires the energy from ATP and the reducing power from NADPH, which are produced during the light-dependent reactions. The carbon dioxide molecules are fixed and transformed into organic compounds, such as glucose, through a series of enzyme-catalyzed reactions in the Calvin cycle.
5.
What is the relationship between the photosystems and the Calvin cycle?
Correct Answer
C. The pHotosystems transfer energy to the Calvin cycle through ATP and NADpH.
Explanation
The photosystems transfer energy to the Calvin cycle through ATP and NADPH. This is because during photosynthesis, the photosystems in the thylakoid membrane of chloroplasts capture light energy and convert it into chemical energy in the form of ATP and NADPH. These energy-rich molecules are then used in the Calvin cycle, which takes place in the stroma of the chloroplasts, to convert carbon dioxide into sugars. Therefore, the photosystems play a crucial role in transferring energy to the Calvin cycle for the synthesis of sugars.
6.
Which of the following statements best describes the process of photosynthesis?
Correct Answer
D. Chloroplasts absorb sunlight and store chemical energy.
Explanation
Chloroplasts are the organelles in plant cells responsible for photosynthesis. During photosynthesis, chloroplasts absorb sunlight and convert it into chemical energy in the form of glucose, which is stored for later use. This process occurs in the chloroplasts' thylakoid membrane, where chlorophyll, a pigment in chloroplasts, captures the energy from sunlight. Oxygen is released as a byproduct of photosynthesis, while carbon dioxide is used in the process to produce glucose. Therefore, the statement "Chloroplasts absorb sunlight and store chemical energy" best describes the process of photosynthesis.
7.
What is the term for an organism that makes its own source of chemical energy?
Correct Answer
B. Producer
Explanation
A producer is an organism that is capable of producing its own source of chemical energy through the process of photosynthesis. This process involves converting sunlight, carbon dioxide, and water into glucose and oxygen. Producers, such as plants and some types of bacteria, play a vital role in ecosystems as they are able to convert solar energy into usable energy for other organisms.
8.
The main light-absorbing molecules found in plant leaves are called
Correct Answer
C. ChloropHyll
Explanation
Chlorophyll is the correct answer because it is the main light-absorbing pigment found in plant leaves. It is responsible for capturing sunlight and converting it into chemical energy through the process of photosynthesis. Chlorophyll molecules are located within the chloroplasts, which are the organelles where photosynthesis takes place. Thylakoids are membrane structures within the chloroplasts where the chlorophyll is embedded. Grana are stacks of thylakoids. However, both thylakoids and grana are not the main light-absorbing molecules but rather the structures that contain chlorophyll.
9.
The function of the light-dependent reactions is to
Correct Answer
B. Capture and transfer energy.
Explanation
The function of the light-dependent reactions in photosynthesis is to capture and transfer energy. During these reactions, light energy is absorbed by pigments in the chloroplasts, such as chlorophyll, and converted into chemical energy in the form of ATP and NADPH. These energy-rich molecules are then used in the subsequent light-independent reactions (Calvin cycle) to build sugars, such as glucose, from carbon dioxide and water. Therefore, the light-dependent reactions play a crucial role in capturing and transferring energy from sunlight to power the synthesis of organic molecules.
10.
The light-independent reactions of photosynthesis need
Correct Answer
A. Carbon dioxide.
Explanation
The light-independent reactions of photosynthesis, also known as the Calvin cycle, are responsible for converting carbon dioxide into glucose. During this process, carbon dioxide molecules are combined with other molecules to form glucose, which is used as a source of energy for the plant. Oxygen is produced as a byproduct of the light-dependent reactions, not the light-independent reactions. Water is also needed for photosynthesis, but it is used in the light-dependent reactions to provide electrons for the production of ATP. Cellulose is a carbohydrate that makes up the cell walls of plants, but it is not directly involved in the light-independent reactions.
11.
What are the products of photosynthesis?
Correct Answer
B. Glucose and oxygen
Explanation
Photosynthesis is the process by which plants convert sunlight, carbon dioxide, and water into glucose (a type of sugar) and oxygen. Glucose is the primary product of photosynthesis and serves as a source of energy for the plant. Oxygen is released as a byproduct of this process and is essential for the survival of many organisms, including humans.
12.
What is the ultimate source of energy in almost every food chain?
Correct Answer
A. The sun
Explanation
The ultimate source of energy in almost every food chain is the sun. Producers, such as plants, use sunlight to perform photosynthesis and convert it into chemical energy. This energy is then passed on to consumers, such as herbivores, who eat the producers. The energy continues to flow through the food chain as consumers are eaten by other consumers. Ultimately, all the energy in the food chain can be traced back to the sun, making it the ultimate source of energy.
13.
In the diagram to the right, the structure labeled C is the ___.
Correct Answer
A. Stroma
Explanation
In the diagram, the structure labeled C is the stroma. The stroma is the fluid-filled space inside the chloroplasts where the light-independent reactions of photosynthesis occur. It surrounds the thylakoid membranes, which are responsible for the light-dependent reactions. The stroma contains enzymes and other molecules necessary for the synthesis of glucose during photosynthesis. Therefore, the stroma is the correct answer in this case.
14.
In the diagram to the right, the structure labeled D is the ___.
Correct Answer
C. Granum
Explanation
In the diagram to the right, the structure labeled D is the granum. The granum is a stack of thylakoid membranes found in the chloroplasts of plant cells. These thylakoid membranes contain the pigment chlorophyll, which is responsible for capturing light energy during photosynthesis. The granum plays a crucial role in the light-dependent reactions of photosynthesis, where light energy is converted into chemical energy to produce ATP and NADPH.
15.
In the diagram to the right, the structure labeled E is the ___.
Correct Answer
D. Thylakoid membranes
Explanation
In the given diagram, the structure labeled E appears to be a series of interconnected membranous sacs, which are characteristic of thylakoid membranes. Thylakoid membranes are found within chloroplasts and are responsible for carrying out the light-dependent reactions of photosynthesis. They contain the pigment chlorophyll, which captures light energy and converts it into chemical energy. The arrangement of the thylakoid membranes in stacks called grana allows for efficient light absorption and energy conversion. Therefore, the correct answer is thylakoid membranes.
16.
The purpose of the light reactions is to___.
Correct Answer
A. Make ATP and NADpH for use in the Calvin cycle
Explanation
The purpose of the light reactions is to make ATP and NADPH for use in the Calvin cycle. During the light reactions of photosynthesis, light energy is captured by chlorophyll and other pigments in the thylakoid membranes of the chloroplasts. This energy is then used to convert ADP and inorganic phosphate into ATP, which is an energy carrier molecule. Additionally, the light energy is also used to convert NADP+ into NADPH, which is a reducing agent that provides the necessary electrons for the Calvin cycle, where glucose is ultimately produced.
17.
Which organelle conducts photosynthesis?
Correct Answer
A. Chloroplast
Explanation
The correct answer is chloroplast. Chloroplasts are organelles found in plant cells that are responsible for conducting photosynthesis. They contain chlorophyll, a pigment that captures sunlight and converts it into energy. During photosynthesis, chloroplasts use this energy to convert carbon dioxide and water into glucose, a form of stored energy. This process is essential for plants to produce their own food and release oxygen into the atmosphere. Mitochondria, nucleus, and Golgi body are other organelles involved in different cellular functions but not directly related to photosynthesis.
18.
Where in the chloroplast does the Calvin Cycle occur?
Correct Answer
A. Stroma
Explanation
The Calvin Cycle occurs in the stroma of the chloroplast. The stroma is the fluid-filled region inside the chloroplast, surrounding the thylakoid membrane. It is where the second stage of photosynthesis takes place, after the light-dependent reactions occur in the thylakoid membrane. In the Calvin Cycle, carbon dioxide is converted into glucose using the energy from ATP and NADPH, which are produced during the light-dependent reactions. Therefore, the stroma is the correct answer as it is the specific location where the Calvin Cycle occurs.
19.
Where in the chloroplast do the light reactions occur?
Correct Answer
B. Thylakoid membrane
Explanation
The thylakoid membrane is where the light reactions occur in the chloroplast. This membrane is located inside the chloroplast and contains chlorophyll, which is responsible for capturing light energy. During the light reactions, light energy is absorbed by chlorophyll and used to convert water into oxygen and high-energy molecules such as ATP and NADPH. These molecules are then used in the subsequent dark reactions of photosynthesis to produce glucose. Therefore, the thylakoid membrane plays a crucial role in the initial step of photosynthesis by capturing and converting light energy.
20.
Which of the following is another name for the Calvin Cycle?
Correct Answer
A. The dark reactions
Explanation
The Calvin Cycle is often referred to as the dark reactions because it does not directly require light energy to occur. It takes place in the stroma of the chloroplasts and is responsible for converting carbon dioxide into glucose through a series of chemical reactions. While the light reactions and the light dependent reaction are part of the photosynthesis process, they are not alternate names for the Calvin Cycle. The photosystems are also involved in photosynthesis but do not specifically refer to the Calvin Cycle.
21.
How many photosystems are used during photosynthesis in most plants?
Correct Answer
A. Two
Explanation
During photosynthesis, most plants use two photosystems. Photosystems are complexes of proteins and pigments located in the thylakoid membrane of chloroplasts. They are responsible for capturing light energy and initiating the process of photosynthesis. The two photosystems, known as photosystem I and photosystem II, work together to absorb light at different wavelengths and transfer electrons to generate energy-rich molecules like ATP and NADPH. This dual system allows plants to efficiently capture and utilize light energy for the synthesis of carbohydrates.