Foetal hemoglobin has great affinity than adult hemoglobin because

Correct Answer: A

Rationale: The correct answer is A because 2,3 DPG binds less avidly to the Gamma polypeptide chain in foetal hemoglobin, resulting in a higher affinity for oxygen. This is due to structural differences between foetal and adult hemoglobin. Choice B is incorrect as high concentration alone does not determine affinity. Choice C is incorrect as the source of oxygen does not affect hemoglobin's affinity. Choice D is incorrect as the speed of oxygen binding does not necessarily correlate with affinity.

Correct Answer: A

Rationale: The correct answer is A: Emphysema. Emphysema leads to an increase in lung compliance due to the destruction of alveolar walls, resulting in decreased elastic recoil. This decreased recoil makes it easier for the lungs to expand and increases overall lung compliance. Incorrect choices: B: Pulmonary fibrosis - Pulmonary fibrosis causes lung tissue scarring and stiffening, resulting in decreased lung compliance. C: Pleural effusion - Pleural effusion is an accumulation of fluid in the pleural space, which can restrict lung expansion and decrease lung compliance. D: Acute respiratory distress syndrome (ARDS) - ARDS causes inflammation and fluid buildup in the lungs, leading to decreased lung compliance due to increased stiffness and reduced ability to expand.

Correct Answer: C

Rationale: The correct answer is C: "Do you currently smoke, or have you ever smoked?" Smoking is the most significant risk factor for respiratory diseases, including lung cancer, chronic obstructive pulmonary disease, and emphysema. Asking about smoking history is crucial in assessing lung disease risk. Rationale: 1. Smoking is the leading cause of preventable death worldwide. 2. Smoking damages the lungs and increases the risk of developing various respiratory conditions. 3. Current and past smoking status helps determine the level of risk for lung disease. 4. Tobacco smoke contains harmful chemicals that can lead to lung damage over time. Summary: A: Occupational exposure is a risk factor, but smoking has a stronger association with respiratory diseases. B: Family history is relevant but not as directly linked to individual behavior and risk as smoking. D: Air pollution can contribute to lung issues, but personal smoking history has a more direct impact on lung health.

Correct Answer: B

Rationale: The correct answer is B: intrapleural pressure. Intrapleural pressure remains negative throughout the respiratory cycle due to the opposing forces of the elastic recoil of the lungs and the chest wall. This negative pressure keeps the lungs inflated and facilitates breathing. In contrast, intrapulmonary (A) and intra-alveolar (C) pressures fluctuate during inhalation and exhalation, becoming positive and negative, respectively. Atmospheric pressure (D) remains relatively constant and serves as the reference point for pressure changes in the respiratory system.

Correct Answer: B

Rationale: The correct answer is B: bound to hemoglobin. This is because hemoglobin is the protein in red blood cells that carries oxygen from the lungs to tissues throughout the body. Oxygen binds to the iron atoms in hemoglobin, forming oxyhemoglobin. This accounts for the majority of oxygen transport in the blood. A: Dissolved in plasma is incorrect as only a small fraction of oxygen is carried this way. C: In ionic form as a solute in plasma is incorrect as oxygen is not typically found in ionic form in the blood. D: Bound to the same protein as carbon dioxide is incorrect as oxygen binds to hemoglobin, while carbon dioxide primarily binds to different proteins such as carbonic anhydrase.