Which hormone, produced by the adrenal glands, prepares the body for a 'fight or flight' response by increasing heart rate, dilating airways, and mobilizing energy stores?

Correct Answer: C

Rationale: Epinephrine, also known as adrenaline, is the hormone produced by the adrenal glands that prepares the body for a 'fight or flight' response. It increases heart rate, dilates airways, and mobilizes energy stores to provide the body with the necessary resources to respond to a perceived threat or stressor. Cortisol, although produced by the adrenal glands, is not responsible for the 'fight or flight' response; it is involved in regulating metabolism, immune response, and stress. Aldosterone, another hormone produced by the adrenal glands, primarily regulates electrolyte and fluid balance. Insulin, produced by the pancreas, is responsible for regulating blood sugar levels and is not directly involved in the 'fight or flight' response.

Correct Answer: B

Rationale: In the balanced chemical equation for the combustion of methane, CH₄ + 2O₂ → CO₂ + 2H₂O, the coefficient of oxygen (O₂) is 2. This indicates that two molecules of oxygen are required to react with one molecule of methane to produce carbon dioxide and water, ensuring the equation is balanced. Choice A is incorrect because the coefficient of oxygen is not 1 but 2. Choices C and D are incorrect as they do not represent the correct coefficient of oxygen in the balanced equation. Understanding the coefficients in a balanced chemical equation is crucial for accurately representing the stoichiometry of the reaction.

Correct Answer: D

Rationale: Volume is the measure of the total amount of space occupied by an object. Mass refers to the amount of matter in an object, density is the mass per unit volume, and weight is the force of gravity acting on an object. When determining the space occupied by an object, volume is the appropriate measurement to consider. Therefore, the correct answer is D. Choices A, B, and C are incorrect as they do not directly indicate the total amount of space occupied by an object. Mass, density, and weight are relevant in different contexts and measurements compared to volume.

Correct Answer: C

Rationale: The correct answer is the Ideal Gas Law (Choice C). The ideal gas law, PV = nRT, describes the relationship between pressure (P), volume (V), temperature (T), and the number of moles of gas (n) for an ideal gas. It states that the product of pressure and volume is directly proportional to the absolute temperature of the gas when the number of moles is held constant. This law is a fundamental principle in understanding the behavior of ideal gases. Choices A, B, and D are incorrect. The Law of conservation of energy (Choice A) pertains to the principle that energy cannot be created or destroyed; Newton's laws of motion (Choice B) describe the relationship between the motion of an object and the forces acting on it; Archimedes' principle (Choice D) deals with the buoyant force exerted on an object immersed in a fluid. These principles are not directly related to the relationship between pressure, volume, and temperature for ideal gases.

Correct Answer: B

Rationale: The correct answer is increasing pressure. According to Henry's Law, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. Therefore, increasing pressure would force more gas molecules into the liquid, leading to an increase in solubility. Conversely, decreasing temperature, decreasing surface area, and increasing particle size would not directly impact the solubility of a gas in a liquid. Decreasing temperature typically decreases solubility as gases are less soluble at lower temperatures. Decreasing surface area and increasing particle size are related to surface area and not the pressure above the liquid, thus not affecting solubility as pressure does.

Correct Answer: B

Rationale: Aseptic meningitis is typically caused by viral infections, such as enteroviruses (e.g., coxsackievirus, echovirus), herpes simplex virus, varicella-zoster virus, and others. These viruses can infect the meninges, leading to inflammation and symptoms of meningitis without the presence of bacteria. While bacterial meningitis is a serious and life-threatening condition, aseptic meningitis caused by viruses is usually less severe and has a better prognosis. Fungi and parasites are less common causes of meningitis compared to bacteria and viruses.

Correct Answer: B

Rationale: The main organ responsible for producing enzymes is the pancreas. Enzymes are proteins that act as biological catalysts to speed up chemical reactions in the body. The pancreas produces and releases digestive enzymes that help break down carbohydrates, proteins, and fats in the small intestine to aid in the digestion and absorption of nutrients. While the liver also plays a role in producing bile, which helps in the digestion and absorption of fats, the primary organ responsible for producing enzymes is the pancreas. The stomach produces gastric juices containing hydrochloric acid and pepsin to help break down food, but it is not the primary organ for enzyme production. The small intestine is where most nutrient digestion and absorption occur; however, it receives enzymes from organs like the pancreas rather than producing them itself.

Correct Answer: B

Rationale: Transcription is the correct answer. Transcription is the process of making copies of RNA from DNA. During transcription, the enzyme RNA polymerase binds to a specific region of DNA and synthesizes a complementary RNA strand based on the DNA template. This process is essential for gene expression and protein synthesis in cells. Replication (option A) refers to the process of making copies of DNA, not RNA. Translation (option C) is the process of synthesizing proteins from mRNA, not making copies of RNA from DNA. DNA repair (option D) involves mechanisms that cells use to repair damaged DNA, not the process of making RNA copies from DNA.

Correct Answer: C

Rationale: Work is done on an object whenever a force causes displacement in the object's position. According to the work-energy principle, work is calculated as the force applied multiplied by the distance the object moves in the direction of the force. Therefore, work can occur whenever there is a force exerted on the object resulting in displacement, regardless of whether the object's velocity changes or it is lifted vertically. Choice A is incorrect because work can be done even without a change in velocity. Choice B is incorrect as work requires both force and displacement, not just the application of force. Choice D is incorrect because work is not limited to vertical lifting; it can happen in any direction as long as there is a force causing displacement.