Vasopressin is normally secreted when a deficit of water develops in the body.

Correct Answer: A

Rationale: Step 1: Vasopressin is also known as antidiuretic hormone and helps regulate water balance by acting on the kidneys. Step 2: When the body detects a deficit of water, vasopressin is secreted to prevent water loss. Step 3: Therefore, the statement that vasopressin is normally secreted when a deficit of water develops in the body is true. Summary: Option A is correct because vasopressin is indeed secreted in response to water deficit. Options B, C, and D are incorrect as they do not provide the accurate explanation for the secretion of vasopressin in response to water deficit.

Correct Answer: B

Rationale: The correct answer is B: FALSE. Enzymes can be affected by various factors, not just acidosis. Enzyme activity can be influenced by pH, temperature, substrate concentration, and enzyme concentration. Acidosis, which is a condition of increased acidity in the blood and body tissues, can certainly affect enzyme activity, but it is not the only factor. Therefore, stating that enzyme activity is affected only by acidosis is incorrect. Choices A, C, and D are not the correct answer because they do not accurately reflect the relationship between enzyme activity and acidosis.

Correct Answer: A

Rationale: The correct answer is A: TRUE. The respiratory system plays a crucial role in regulating the body's pH by controlling the levels of carbon dioxide in the blood through respiration. However, it can only partially counteract deviations in body pH because it cannot rapidly adjust to extreme changes. Other choices (B, C, D) are incorrect because the respiratory system does have a role in pH regulation, even though it is not the only system involved.

Correct Answer: B

Rationale: The correct answer is B: FALSE. During respiratory compensation for metabolic alkalosis, breathing actually becomes faster and deeper to expel excess carbon dioxide and increase blood pH. Slower and shallower breathing would exacerbate alkalosis by retaining more CO2. Choice A is incorrect because it contradicts the physiological response to metabolic alkalosis. Choices C and D are not applicable since they do not provide any useful information regarding the question.

Correct Answer: A

Rationale: Rationale: 1. Hyperventilation leads to increased exhalation of CO2. 2. Reduced CO2 levels result in decreased carbonic acid formation. 3. The decrease in carbonic acid causes alkalosis. 4. Therefore, respiratory alkalosis occurs due to CO2 being removed faster than produced. Other choices (B, C, D) are incorrect as they do not provide a logical explanation for respiratory alkalosis.