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 through which plants convert sunlight, water, and carbon dioxide into glucose and oxygen. This process occurs in the chloroplasts of plant cells, specifically in the chlorophyll pigments. During photosynthesis, sunlight is absorbed by chlorophyll, which then converts the energy into chemical energy to produce glucose. This glucose is used by plants as a source of energy for growth, development, and other metabolic processes.
2.
Which of the following takes place in the light-dependent reactions of photosynthesis?
Correct Answer
B. Energy is captured.
Explanation
In the light-dependent reactions of photosynthesis, energy is captured from sunlight by the pigment chlorophyll. This energy is then used to convert water into oxygen and produce ATP, the energy currency of cells, as well as NADPH, a molecule used in the subsequent dark reactions to convert carbon dioxide into sugars. Therefore, the correct answer is "Energy is captured."
3.
Where do the hydrogen ions for the photosystems of the light-dependent reactions come from?
Correct Answer
D. Water
Explanation
In the light-dependent reactions of photosynthesis, the hydrogen ions for the photosystems come from water. During photosynthesis, water molecules are split by the process of photolysis, releasing oxygen, electrons, and hydrogen ions. The electrons are then used in the photosystems to generate ATP and NADPH, which are energy-rich molecules used in the Calvin cycle to produce sugars. Therefore, water is the source of hydrogen ions that are essential for the light-dependent reactions of photosynthesis.
4.
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 and generating a proton gradient, which is used to produce ATP during the light-dependent reactions of photosynthesis. The thylakoid membrane is where the pigments and protein complexes involved in photosynthesis are located, making it the ideal location for the electron transport chain to occur.
5.
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 undergoes a series of chemical reactions to produce sugars. This process is also known as the Calvin-Benson cycle. The carbon dioxide molecules are combined with molecules from the previous steps of photosynthesis to form glucose and other sugars, which are important sources of energy for plants and other organisms. This step does not directly involve the breakdown of water, production of oxygen, or the transfer of NADPH or energized electrons.
6.
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 membranes 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 glucose and other organic compounds. Therefore, the photosystems play a crucial role in providing the energy necessary for the Calvin cycle to occur.
7.
Which of the following statements best describes the process of photosynthesis?
Correct Answer
D. Chloroplasts absorb sunlight and store chemical energy.
Explanation
The process of photosynthesis involves chloroplasts, which are organelles found in plant cells. Chloroplasts contain chlorophyll, a pigment that absorbs sunlight. During photosynthesis, chloroplasts absorb sunlight and convert it into chemical energy in the form of glucose or other simple sugars. This chemical energy is stored in the plant cells and can be used for various metabolic processes. Therefore, the statement "Chloroplasts absorb sunlight and store chemical energy" best describes the process of photosynthesis.
8.
What is the term for an organism that makes its own source of chemical energy?
Correct Answer
B. AutotropH
Explanation
Autotroph is the correct answer because an autotroph is an organism that is capable of producing its own source of chemical energy through processes like photosynthesis or chemosynthesis. Autotrophs can convert sunlight or inorganic compounds into organic molecules that can be used as energy sources. This ability to self-produce energy sets autotrophs apart from other organisms that rely on consuming other organisms for energy. Examples of autotrophs include plants, algae, and some bacteria.
9.
The function of the light-dependent reactions is to
Correct Answer
B. Capture and transfer energy
Explanation
The light-dependent reactions in photosynthesis capture and transfer energy from sunlight to convert it into chemical energy in the form of ATP and NADPH. These reactions occur in the thylakoid membrane of chloroplasts, where pigments such as chlorophyll absorb light energy. This energy is then used to split water molecules, releasing oxygen as a byproduct. The captured energy is stored in ATP and NADPH, which are essential for the subsequent light-independent reactions to build sugars through the process of carbon fixation. Therefore, the function of the light-dependent reactions is to capture and transfer energy.
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, require carbon dioxide as a raw material. During this process, carbon dioxide molecules are used to produce glucose, which is then converted into cellulose, a structural component of plant cells. Oxygen and water are not directly involved in the light-independent reactions, but they are produced as byproducts of the light-dependent reactions.
11.
What are the products of photosynthesis?
Correct Answer
B. Glucose and oxygen
Explanation
Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to produce glucose (a form of sugar) and oxygen. This is achieved through the conversion of sunlight energy into chemical energy, which is stored in the glucose molecules. Oxygen is released as a byproduct of this process and is essential for many organisms, including humans, for respiration. Therefore, the correct answer is "Glucose and oxygen."
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. This is because producers, such as plants, use sunlight to convert it into chemical energy through the process of photosynthesis. This energy is then passed on to consumers, who eat the producers, and subsequently to other consumers in the food chain. Therefore, the sun is the primary source of energy that fuels the entire food chain.
13.
In the diagram to the right, the structure labeled C is the ___.
Correct Answer
A. Stroma
Explanation
The diagram to the right shows a cellular structure labeled C. The stroma is the fluid-filled region within the chloroplast, where various metabolic reactions occur. It surrounds the thylakoid membranes, which are responsible for the light-dependent reactions of photosynthesis and contain the pigment chlorophyll. The granum refers to a stack of thylakoid membranes. Therefore, based on the information provided, the correct answer is stroma.
14.
In the diagram to the right, the structure labeled D is the ___.
Correct Answer
C. Granum
Explanation
The diagram to the right shows a structure labeled D, which is the granum. The granum is a stack of thylakoid membranes found in the chloroplasts of plant cells. It is responsible for the light-dependent reactions of photosynthesis, where chlorophyll molecules capture sunlight and convert it into chemical energy. The granum's stacked structure allows for a large surface area for chlorophyll molecules to absorb light, maximizing the efficiency of photosynthesis.
15.
In the diagram to the right, the structure labeled E is the ___.
Correct Answer
D. Thylakoid membranes
Explanation
The diagram to the right is depicting a chloroplast, which is the organelle responsible for photosynthesis in plant cells. Within the chloroplast, there are different structures involved in the process. The thylakoid membranes are responsible for capturing light energy and converting it into chemical energy. They are stacked together to form structures called grana. The stroma is the fluid-filled space surrounding the thylakoid membranes. Chlorophyll is the pigment found within the thylakoid membranes that absorbs light energy. Therefore, the structure labeled E in the diagram is the 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 produce ATP and NADPH, which are used as energy and reducing power, respectively, in the Calvin cycle. The light reactions occur in the thylakoid membrane of chloroplasts and involve the absorption of light by chlorophyll molecules. This energy is then used to generate ATP through photophosphorylation and to produce NADPH through the transfer of electrons from water molecules. These energy-rich molecules are essential for the Calvin cycle, where they are used to fix carbon dioxide and produce glucose.
17.
Which molecule is an electron carrier in photosynthesis?
Correct Answer
A. NADpH
Explanation
NADPH is an electron carrier in photosynthesis. It acts as a reducing agent, accepting electrons and hydrogen ions to become NADPH. This molecule plays a crucial role in the light-dependent reactions of photosynthesis, where it transfers the high-energy electrons to other molecules, ultimately leading to the production of ATP and the conversion of carbon dioxide into glucose. NADPH is essential for the synthesis of carbohydrates during the Calvin cycle, making it a key molecule in the process of photosynthesis.
18.
The light-dependent reactions of photosynthesis are also known as ___.
Correct Answer
A. pHotosystems
Explanation
The light-dependent reactions of photosynthesis are also known as photosystems. Photosystems are clusters of chlorophyll and other pigments that are responsible for capturing light energy and converting it into chemical energy in the form of ATP and NADPH. These reactions occur in the thylakoid membranes of the chloroplasts and are the first step in the process of photosynthesis.
19.
The light-independent reactions of photosynthesis are also known as ___.
Correct Answer
B. The Calvin Cycle
Explanation
The correct answer is The Calvin Cycle. The light-independent reactions of photosynthesis, also known as the Calvin Cycle, occur in the stroma of the chloroplasts. During this process, carbon dioxide is converted into glucose using the energy from ATP and NADPH produced in the light-dependent reactions. The Calvin Cycle is essential for the synthesis of organic compounds, including carbohydrates, which are used as a source of energy by the plant.
20.
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 light energy during photosynthesis and converting it into chemical energy. Chlorophyll molecules are located within the chloroplasts, which are the organelles where photosynthesis takes place. Thylakoids and grana are structures within the chloroplasts that contain chlorophyll and other components necessary for photosynthesis, but they are not the main light-absorbing molecules themselves.