Biology Exam Practice Quiz On Photosynthesis

When carbon dioxide is removed from a plant's environment, it will have a negative impact on the plant's production of high-energy sugars. This is because carbon dioxide is one of the key ingredients required for photosynthesis, the process by which plants convert sunlight into energy in the form of sugars. Without carbon dioxide, the plant's ability to produce sugars will be reduced, leading to fewer sugars being produced.

A granum is a stack of thylakoids. Thylakoids are membrane-bound compartments found within chloroplasts, which are responsible for carrying out the light-dependent reactions of photosynthesis. The thylakoids contain chlorophyll and other pigments that capture light energy and convert it into chemical energy, which is used to produce ATP and NADPH. These thylakoid membranes are organized into stacks called granum, which allow for efficient light absorption and energy conversion in photosynthesis.

The correct answer is adenine, ribose, phosphate. Adenine is a nitrogenous base, ribose is a five-carbon sugar, and phosphate is a group consisting of one phosphorus atom bonded to four oxygen atoms. These three components make up the structure of adenosine triphosphate (ATP), which is the primary energy currency in cells. Adenine provides the base, ribose forms the backbone, and phosphate groups are attached to the ribose to store and release energy when needed.

ATP is a molecule that consists of ribose, adenine, and phosphate, so the statement "ATP consists of ribose, adenine, and phosphate" is true. ADP forms when ATP releases energy, which is a known process, so the statement "ADP forms when ATP releases energy" is also true. ATP provides energy for the mechanical functions of cells, which is a well-established fact, making the statement "ATP provides energy for the mechanical functions of cells" true. However, used ATP is not discarded by the cell as waste. Instead, it is recycled and regenerated back into ATP through cellular processes, making the statement "used ATP is discarded by the cell as waste" false.

Grass is not an example of a heterotroph because heterotrophs are organisms that obtain their energy by consuming other organisms or organic matter. Grass, on the other hand, is an autotroph, which means it can produce its own food through photosynthesis. It uses sunlight, water, and carbon dioxide to create glucose and oxygen, making it an example of a producer in the food chain.

When a phosphate group is removed from ATP, energy is released. ATP (adenosine triphosphate) is a molecule that stores energy in its high-energy phosphate bonds. When one of these phosphate groups is removed through a hydrolysis reaction, ATP is converted into ADP (adenosine diphosphate), and the released phosphate group carries a negative charge. This release of the phosphate group and the associated negative charge causes a release of energy, which can be used for cellular processes such as muscle contraction, active transport, or synthesis of molecules.

The light-dependent reactions of photosynthesis take place in the thylakoid membranes. These reactions occur within the chloroplasts, specifically in the thylakoid membrane, which is where the chlorophyll molecules are located. The thylakoid membranes contain all the necessary components for the light-dependent reactions, such as the photosystems and electron transport chain, which are responsible for capturing light energy and converting it into chemical energy in the form of ATP and NADPH. Therefore, the correct answer is in the thylakoid membranes.

The Calvin Cycle refers to the light-independent reactions of photosynthesis. These reactions occur in the stroma of chloroplasts and convert carbon dioxide into glucose. Unlike the light-dependent reactions, which require sunlight, the Calvin Cycle can occur in the absence of light. Therefore, the correct answer is light-independent reactions.

Photosynthesis is the process by which plants, algae, and some bacteria convert sunlight, water, and carbon dioxide into oxygen and high-energy sugars. Oxygen is released as a byproduct, while the sugars, such as glucose, are used as a source of energy for the organism. This process occurs in the chloroplasts of plant cells, specifically in the thylakoid membranes where chlorophyll captures sunlight and converts it into chemical energy. Therefore, the correct answer is "oxygen and high-energy sugars."

The statement "a stroma contains a thylakoid" is false. The stroma is a gel-like substance that surrounds the thylakoids in the chloroplast. Thylakoids, on the other hand, are membrane-bound structures within the chloroplast that contain chlorophyll and are responsible for the light-dependent reactions of photosynthesis. The stroma and thylakoids work together to carry out the process of photosynthesis, but they are distinct components within the chloroplast.