Which of the following proteins is iron a component of, responsible for the transport of oxygen in the bloodstream?

Correct Answer: A

Rationale: The correct answer is A: hemoglobin. Hemoglobin is the protein found in red blood cells that is responsible for carrying oxygen from the lungs to the rest of the body. Iron is a crucial component of hemoglobin, binding to oxygen and allowing for its transport. Choice B, transferrin, is involved in iron transport in the blood but not in oxygen transport. Choice C, myoglobin, is a protein found in muscle cells that stores oxygen for muscle use, not transportation in the bloodstream. Choice D, hepcidin, is a peptide hormone that regulates iron absorption in the intestines and iron distribution in the body, but it is not directly involved in oxygen transport.

Correct Answer: D

Rationale: Fluid retention can mask weight loss in ill individuals as the retained fluid adds to body weight, making it difficult to detect true fat or muscle loss. Dehydration (Choice A) would actually lead to weight loss rather than masking it. While a large tumor (Choice B) could contribute to weight loss, it would not mask the weight loss itself. Drug therapy (Choice C) may cause side effects, including weight changes, but it is unlikely to mask significant weight loss in the same way that fluid retention does.

Correct Answer: D

Rationale: The correct answer is D, conducting nutrition assessments. Registered dietitians are responsible for assessing an individual's nutritional status, dietary intake, and health needs. This assessment forms the basis for developing personalized nutrition care plans. Choices A and B involve the administration of specialized nutrition support, which is typically done by healthcare providers with specific training in those areas. Choice C, prescribing diet orders, may fall outside the scope of practice for a dietitian as they focus more on assessment, education, and counseling related to nutrition rather than prescribing medical treatments.

Correct Answer: C

Rationale: Low levels of HDL cholesterol are a strong predictor of coronary heart disease (CHD) risk because HDL helps to remove excess cholesterol from the bloodstream. Choice A is incorrect because low HDL levels are not associated with being underweight but rather with increased CHD risk. Choice B is incorrect as low HDL levels are not more prevalent in males but can affect both genders. Choice D is incorrect as low levels of HDL are indeed a good predictor of CHD risk.

Correct Answer: B

Rationale: Alcohol does contain energy and provides calories, but it is not considered a nutrient. Nutrients are substances that contribute to essential bodily functions. While alcohol may have energy, it does not provide essential vitamins, minerals, or other nutrients necessary for the body's health. Additionally, excessive alcohol consumption can have harmful effects on the body, further supporting why alcohol is not classified as a nutrient.