The mineral that helps control enzyme actions in cell mitochondria that produce and store high-energy compounds is:

Correct Answer: A

Rationale: The correct answer is iron. Iron is essential for enzyme function and energy production within the mitochondria. While cobalt is important for certain enzymes, it is not the primary mineral involved in this specific function. Hemoglobin is a protein in red blood cells that carries oxygen, not a mineral involved in enzyme actions. Vitamin B12 is crucial for nerve function and DNA synthesis but is not directly related to controlling enzyme actions in mitochondria.

Correct Answer: B

Rationale: A normal weight-to-height ratio is a reliable indicator of good nutritional status as it suggests that the person is well-nourished and not underweight or overweight. Small muscle mass (choice A) can indicate malnutrition, a smooth tongue (choice C) can be a sign of vitamin deficiencies, and fragile skin (choice D) can be a sign of poor nutrition or other health issues, but they are not as direct indicators of good nutritional status as a normal weight-to-height ratio.

Correct Answer: A

Rationale: Individuals with optimal nutritional status differ from those with marginal nutritional status in their nutrient reserves. Optimal nutritional status implies having adequate nutrient reserves, which is lacking in marginal status. Clinical signs (choice B) may or may not be present in both groups and are not the differentiating factor between optimal and marginal statuses. Body weight (choice C) can vary for reasons other than nutritional status. The risk of mental illness (choice D) is not directly related to the comparison between optimal and marginal nutritional status.

Correct Answer: C

Rationale: Low income is a significant factor contributing to marginal nutritional status due to limited access to nutritious food. While dependence on caffeine or acute illness can impact health, they are not as directly linked to marginal nutrition as low income. The size of the family unit may affect food distribution within the household but is not as directly related to marginal nutritional status as low income.

Correct Answer: A

Rationale: The correct answer is A: 'nutrient reserves are depleted.' Signs of malnutrition manifest when the body's reserves of essential nutrients are exhausted and can no longer sustain health. Choice B is incorrect because excessive nutrient intake exceeding daily needs does not lead to malnutrition but may cause other health issues. Choice C is incorrect as restricting energy intake may lead to weight loss but not necessarily malnutrition. Choice D is also incorrect as increasing caloric expenditure does not directly cause malnutrition.