Correct Answer: D

Rationale: The endoplasmic reticulum (ER) is not involved in the breakdown of cellular waste products; this function is primarily carried out by lysosomes. The ER is responsible for the synthesis of lipids (fats), transport of materials within the cell, and detoxification of harmful substances. Lysosomes are the organelles responsible for breaking down cellular waste products through processes like autophagy. Therefore, option D is the correct answer as it does not align with the known functions of the endoplasmic reticulum.

Correct Answer: C

Rationale: The correct answer is C: Adrenal gland. The hormone responsible for the 'fight-or-flight' response in stressful situations is produced by the adrenal gland. This hormone is called adrenaline (epinephrine) and is released in response to stress, preparing the body to either fight the stressor or flee from it. The other choices are incorrect because the thyroid gland primarily produces hormones that regulate metabolism, the pituitary gland produces various hormones that control other endocrine glands, and the pancreas produces insulin and glucagon to regulate blood sugar levels.

Correct Answer: B

Rationale: The primary function of coronary arteries is to supply oxygenated blood to the heart muscle itself. The heart is a muscle that needs a constant supply of oxygen and nutrients to function properly. Coronary arteries branch off the aorta and specifically deliver oxygenated blood to the heart muscle, ensuring its proper function. Choice A is incorrect because coronary arteries do not deliver blood throughout the entire body but specifically to the heart. Choice C is incorrect as coronary arteries carry oxygenated blood away from the heart. Choice D is incorrect as the primary function of the coronary arteries is not to regulate blood pressure but rather to provide oxygenated blood to the heart muscle.

Correct Answer: B

Rationale: The recommended daily intake of protein for adults to maintain healthy muscle mass is typically around 1 gram per kilogram of body weight. This amount can vary based on individual factors such as activity level, age, and overall health status. Consuming an adequate amount of protein is essential for muscle repair and growth, as well as overall health and functioning of the body. Choices A, C, and D are incorrect because they suggest protein intake levels that are either too low (A) or unnecessarily high (C and D) for maintaining healthy muscle mass. Excessive protein intake can strain the kidneys and may not provide additional benefits for muscle health beyond the recommended levels.

Correct Answer: A

Rationale: A) Tundra: This biome is characterized by cold temperatures, permafrost (permanently frozen subsoil), and vegetation such as mosses, lichens, and coniferous trees like spruce and fir. The tundra is found in high latitudes near the Arctic Circle and high altitudes in mountainous regions. It is a cold and harsh environment where the ground remains frozen for a significant part of the year. The coniferous trees in this biome are adapted to survive in extreme cold conditions. B) Desert: Deserts are characterized by low precipitation levels and high temperatures, with sparse vegetation adapted to arid conditions. C) Rainforest: Rainforests are characterized by high levels of rainfall, warm temperatures, and dense vegetation with a variety of plant and animal species. D) Savanna: Savannas are tropical grasslands with scattered trees and shrubs, characterized by a distinct wet and dry season. They have a different climate pattern compared to the cold temperatures and permafrost found in the tundra biome. In this case, the description of cold temperatures, permafrost, and coniferous trees aligns most closely with the characteristics of the tundra biome, making option A the correct answer.