Waec Model Questions Vol1 2025 Biology Question 2
Practice objective / multiple choice question 2 from the 2025 Waec Model Questions Vol1 Biology examination.
A desert trekker loses water at a constant rate of 1 L h⁻¹ (combined sweating and respiration) and drinks 0.4 L h⁻¹ of water. Each litre of water deficit raises his plasma osmolality by 5 mOsm·kg⁻¹. His initial plasma osmolality is 285 mOsm·kg⁻¹. Antidiuretic hormone (ADH) secretion starts only when osmolality exceeds 295 mOsm·kg⁻¹, and for every 1 mOsm·kg⁻¹ above this threshold the kidneys reabsorb an additional 0.1 L h⁻¹ of water. How many hours will elapse before his plasma osmolality reaches 300 mOsm·kg⁻¹?
Answer Options
About This Question
This is Waec Model Questions Vol1 2025 Biology Question 2. It is one of the objective questions from the 2025 Waec Model Questions Vol1 Biology examination.
Difficulty level: Medium .
Master the Exam!
You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.