Biology Practice Test, Ch. 8-10

The correct order of the phases of mitosis is prophase, metaphase, anaphase, telophase. In prophase, the chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle fibers form. In metaphase, the chromosomes line up along the equator of the cell and the spindle fibers attach to the centromeres. In anaphase, the sister chromatids separate and move towards opposite poles of the cell. In telophase, the chromosomes reach the poles of the cell, the nuclear membrane reforms, and the spindle fibers disassemble.

The main difference between autotrophs and heterotrophs is how they obtain their energy. Autotrophs are able to produce their own food through photosynthesis or chemosynthesis, while heterotrophs rely on consuming other organisms for energy. This fundamental distinction in energy acquisition sets the two groups apart in terms of their metabolic processes and ecological roles.

Interphase is not a phase of mitosis. It is actually the phase that occurs before mitosis begins, during which the cell prepares for division by growing and replicating its DNA. Mitosis itself consists of prophase, metaphase, anaphase, and telophase, which are the stages where the cell's chromosomes condense, line up at the center, separate, and then form two new nuclei respectively.

Cancer cells do not respond to the signals that regulate the growth of most cells. Unlike normal cells, cancer cells have mutations in their DNA that disrupt the normal signaling pathways controlling cell growth and division. These mutations allow cancer cells to grow and divide uncontrollably, leading to the formation of tumors. As a result, cancer cells are able to evade the normal regulatory mechanisms that prevent excessive cell growth and continue to proliferate despite the presence of growth-regulating signals.

The human body can use ATP in muscles, glycolysis, cellular respiration, and lactic acid fermentation as energy sources. However, alcoholic fermentation is not a process that occurs in the human body for energy production. Alcoholic fermentation is a metabolic process that occurs in yeast and some bacteria, where glucose is converted into ethanol and carbon dioxide. In humans, this process does not occur, and therefore alcoholic fermentation is not a viable energy source for the human body.

Option 1 is the correct answer because it represents the chemical equation of photosynthesis. The equation shows the conversion of carbon dioxide and water into glucose and oxygen, which is the process that occurs during photosynthesis in plants. This equation is widely recognized and accepted as the representation of photosynthesis in the scientific community.

ATP (adenosine triphosphate) is actually great for transferring and storing energy. It is commonly referred to as the "energy currency" of the cell as it provides the necessary energy for various cellular processes. ATP transfers energy by breaking the high-energy phosphate bond, releasing energy that can be used by the cell. Although ATP is not suitable for long-term energy storage, it is efficient for short-term energy transfer within cells. Therefore, the given answer is False.

One Calorie (C) is equal to 1000 calories (c). The capital "C" represents kilocalories, which is a unit commonly used to measure the energy content of food. On the other hand, the lowercase "c" represents calories, which is a smaller unit of energy. Therefore, there are 1000 calories in one Calorie.

A calorie is a unit of measurement for energy. It represents the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius.

The first process in the light-dependent reactions of photosynthesis is light absorption. This is when chlorophyll molecules in the thylakoid membranes of the chloroplasts absorb light energy from the sun. This energy is then used to initiate the subsequent processes of electron transport, oxygen production, and ATP formation. However, light absorption is the initial step that allows the conversion of light energy into chemical energy, which is essential for the rest of the reactions to occur.

The first process in the light-dependent reactions of photosynthesis is light absorption. In this process, light energy is absorbed by chlorophyll molecules in the thylakoid membranes of the chloroplasts. This absorbed light energy is then used to initiate a series of reactions that ultimately result in the production of ATP and NADPH, which are essential for the synthesis of glucose during the subsequent dark reactions of photosynthesis.

Photosynthesis is the process by which plants convert sunlight into energy. This process occurs in the chloroplasts, which are organelles found in plant cells. Chloroplasts contain chlorophyll, a pigment that absorbs sunlight, and other necessary components for photosynthesis. The mitochondria is responsible for cellular respiration, not photosynthesis. The golgi apparatus is involved in protein modification and transport, while the nucleus contains the cell's genetic material. Therefore, the correct answer is the chloroplast.

In cells, the energy available in food is used to make an energy-rich compound called glucose. Glucose is a simple sugar that serves as the primary source of energy for cellular processes. It is broken down through a series of metabolic reactions to produce ATP, which is the main energy currency of the cell. ATP can then be used to power various cellular activities, such as muscle contractions, active transport, and synthesis of molecules. ADP, on the other hand, is the product of ATP hydrolysis and needs to be converted back to ATP to replenish the cell's energy supply. Water, although essential for cellular processes, does not directly store or release energy.

Cells can regenerate ATP from ADP as needed by using energy in foods like glucose. This is because ATP (adenosine triphosphate) is the main energy currency of cells, and it can be formed by adding a phosphate group to ADP (adenosine diphosphate) through a process called phosphorylation. This process occurs during cellular respiration, where glucose is broken down to release energy, which is then used to regenerate ATP. Therefore, the statement "Cells can regenerate ATP from ADP as needed by using energy in foods like glucose" is true.

The characteristics of ATP make it exceptionally useful as the basic energy source of all cells.

Chromatids are replicated copies of chromosomes that are attached to each other at a specific region called the centromere. The centromere plays a crucial role in ensuring the accurate separation of chromatids during cell division. It serves as the attachment point for the spindle fibers, which are responsible for pulling the chromatids apart and distributing them equally to the daughter cells. Therefore, the correct answer is centromere.

The first step in releasing the energy of glucose in the cell is known as glycolysis. Glycolysis is a metabolic pathway that occurs in the cytoplasm of the cell and involves the breakdown of glucose into two molecules of pyruvate. This process does not require oxygen and is the initial step in both aerobic and anaerobic respiration. It produces a small amount of ATP and NADH, which can then be used in further energy production processes.

The larger a cell becomes, the more demands the cell places on its DNA and the more trouble the cell has moving enough nutrients and wastes across the cell membrane.

In the Calvin cycle, 6 carbon molecules in the form of carbon dioxide are added each time the process begins. These carbon molecules are then converted into organic molecules through a series of enzymatic reactions. This process is crucial for plants to produce glucose and other organic compounds necessary for their growth and survival.

Plants and some other types of organisms are able to use light energy from the sun to produce food.

The Calvin cycle occurs in the stroma of the chloroplast. The stroma is the fluid-filled space inside the chloroplast, where various enzymes and molecules required for the Calvin cycle are located. This is where carbon dioxide is fixed and converted into organic molecules, using the ATP and NADPH produced during the light-dependent reactions in the thylakoid membrane. The stroma provides an ideal environment for the Calvin cycle to take place, as it is where the necessary enzymes and substrates are present.

Photosynthesis is the process by which plants convert sunlight, water, and carbon dioxide into glucose (sugars) and oxygen. The energy from sunlight is used to split water molecules, releasing oxygen as a byproduct. Carbon dioxide is then taken in by the plant and combined with the energy from sunlight to produce glucose. Therefore, the correct answer is sugars and oxygen.

The process of cell division, also known as mitosis, results in the formation of two daughter cells. During mitosis, the parent cell's genetic material is duplicated and then evenly distributed between the two daughter cells. This ensures that each daughter cell receives a complete set of chromosomes and genetic information. The formation of two daughter cells allows for growth, repair, and replacement of cells in the body.

Fermentation is actually anaerobic, not aerobic. In fermentation, the process of breaking down glucose into simpler compounds occurs without the presence of oxygen. This process is commonly observed in yeast and bacteria, where glucose is converted into ethanol or lactic acid. Unlike aerobic respiration, which requires oxygen, fermentation is a form of cellular respiration that occurs in the absence of oxygen.

Glucose is a complex sugar molecule that serves as a major source of energy for living organisms. It contains many chemical bonds that can be broken down during cellular respiration to release energy. On the other hand, ATP (adenosine triphosphate) is a molecule that functions as the primary energy carrier in cells. While ATP is crucial for energy transfer within cells, it stores relatively less chemical energy compared to glucose. Therefore, the statement that a single molecule of glucose stores more than 90 times the chemical energy of a molecule of ATP is true.

Photosynthesis is the process by which plants convert light energy into chemical energy in the form of glucose. In addition to light and chlorophyll, photosynthesis requires water and carbon dioxide. Water is a source of hydrogen ions needed for the synthesis of glucose, while carbon dioxide is the source of carbon atoms that are incorporated into glucose molecules. Oxygen is produced as a byproduct of photosynthesis, but it is not required for the process itself. Sugars are the end product of photosynthesis and are not necessary for the process to occur.

The light-dependent reactions of photosynthesis occur in the thylakoid membrane. This is where the chlorophyll molecules are located, along with other pigments and proteins that are involved in capturing light energy. The thylakoid membrane is responsible for converting light energy into chemical energy through a series of reactions, including the splitting of water molecules and the production of ATP and NADPH. The products of the light-dependent reactions are then used in the stroma, where the light-independent reactions (Calvin cycle) take place.

The rate at which materials enter and leave through the cell membrane depends on the cell's surface area. This is because the cell membrane is responsible for the exchange of materials between the cell and its environment. A larger surface area allows for more efficient transport of molecules, as there is a greater area available for diffusion or active transport. On the other hand, the cell's volume, weight, and mass do not directly affect the rate of material exchange through the cell membrane.

The electron transport chain uses the high-energy electrons from the Krebs cycle to convert ADP (adenosine diphosphate) to ATP (adenosine triphosphate). ATP is the primary source of energy for cellular processes, and the electron transport chain is responsible for generating a large amount of ATP through oxidative phosphorylation. This process involves the transfer of electrons along a series of protein complexes, which creates a proton gradient across the inner mitochondrial membrane. The flow of protons back across the membrane drives the synthesis of ATP from ADP and inorganic phosphate.

As a cell grows larger, its volume increases at a faster rate compared to its surface area. This means that the surface area to volume ratio decreases. A smaller surface area to volume ratio is disadvantageous for a cell because it limits the rate at which nutrients and waste products can move in and out of the cell. Therefore, the larger a cell becomes, the smaller its surface area to volume ratio.

Glycolysis is the initial step in cellular respiration, where glucose is broken down into pyruvate. During this process, a net gain of 2 ATP molecules is produced. This occurs through substrate-level phosphorylation, where high-energy phosphate groups are transferred from intermediate molecules to ADP, forming ATP. Therefore, the correct answer is 2 ATP molecules.

Glycolysis is the initial step in cellular respiration, where glucose is broken down into pyruvate. This process occurs in the cytoplasm and does not require oxygen. While glycolysis does produce a small amount of energy in the form of ATP, it is relatively inefficient compared to the subsequent steps of cellular respiration. The majority of the energy is released during the later stages of respiration, such as the Krebs cycle and oxidative phosphorylation. Therefore, it is true that glycolysis releases only a small amount of energy.

Mark Kirschner and Tim Hunt are the correct answers because they are both biologists who were responsible for the discovery of the protein cyclin.

NADPH is the correct answer because it is a product of the light-dependent reactions of photosynthesis. It is a high-energy molecule that carries the energy and electrons needed for the Calvin cycle, which is the process that converts carbon dioxide into glucose. NADPH donates its electrons to the Calvin cycle, providing the energy required for the synthesis of glucose. ADP, H(2)O, and pyruvic acid are not directly involved in the Calvin cycle and do not serve as a source of energy for it.

Cyclins regulate the timing of the cell cycle in eukaryotic cells. These proteins bind to and activate cyclin-dependent kinases (CDKs), which are enzymes that control the progression of the cell cycle. By forming complexes with CDKs, cyclins help to regulate the transition between different phases of the cell cycle, such as G1, S, G2, and M phases. The levels of cyclins fluctuate throughout the cell cycle, with different cyclins being expressed at specific stages to ensure proper cell cycle progression.

Glycolysis, lactic acid fermentation, and alcoholic fermentation can occur in the absence of oxygen. Glycolysis is the process of breaking down glucose into pyruvate, and it can occur in both aerobic and anaerobic conditions. Lactic acid fermentation occurs when pyruvate is converted into lactic acid, and it is commonly observed in muscle cells during intense exercise. Alcoholic fermentation is a process where pyruvate is converted into ethanol and carbon dioxide, and it is commonly used in the production of alcoholic beverages. These processes are all examples of anaerobic respiration, which does not require oxygen.

External regulators in the cell cycle play a crucial role in directing cells to proceed through the cycle and then stop. These regulators ensure that the cell cycle progresses in a controlled manner, allowing for proper cell growth, division, and differentiation. Once the necessary checkpoints and signals are met, the external regulators signal the cell to proceed through the cycle. However, they also have the ability to halt the cell cycle if any abnormalities or errors are detected, preventing the cells from growing uncontrollably and potentially leading to diseases such as cancer.

Cellular respiration is the process by which cells convert glucose and oxygen into energy, carbon dioxide, and water. Glucose is not released as waste in cellular respiration as it is the initial reactant. However, carbon dioxide and water are byproducts of this process and are released as waste. Therefore, the correct answer is carbon dioxide and water.

During alcoholic fermentation, yeast converts sugar into alcohol and carbon dioxide. In the context of bread making, yeast is added to the dough, and as it ferments, it produces carbon dioxide gas. This gas gets trapped in the dough, creating bubbles, which causes the dough to rise. The carbon dioxide is responsible for the light and fluffy texture of bread. Therefore, carbon dioxide is the substance produced by alcoholic fermentation that makes bread dough rise.

NADPH, ATP, hydrogen ions, and oxygen are all produced in the light-dependent reactions of photosynthesis. During these reactions, light energy is absorbed by chlorophyll in the thylakoid membranes of the chloroplasts. This energy is then used to generate ATP and NADPH, which are both energy-rich molecules that are essential for the next stage of photosynthesis. Hydrogen ions are also produced as a result of the splitting of water molecules, and oxygen is released as a byproduct. These reactions occur in the presence of light and take place in the thylakoid membranes of the chloroplasts.

NADH is needed to begin the process of glycolysis. NADH is an electron carrier that is produced during the conversion of glucose to pyruvate in the cytoplasm. It plays a crucial role in transferring electrons to the electron transport chain, which generates ATP through oxidative phosphorylation. NADH is essential for the breakdown of glucose and the production of energy in the form of ATP during glycolysis.