Gce Model Questions Vol1 2025 Biology Question 23

Practice objective / multiple choice question 23 from the 2025 Gce Model Questions Vol1 Biology examination.

Gce Model Questions Vol1 2025 Biology Objective / Multiple Choice Medium Difficulty
Question 23 GCE_MODEL_QUESTIONS_VOL1 • 2025 • BIOLOGY • objective

In a female frog, estrogen is produced at a constant rate of \(5\ \mu\text{g day}^{-1}\) and is removed by first‑order degradation with a rate constant of \(0.1\ \text{day}^{-1}\). When the estrogen concentration reaches \(30\ \mu\text{g}\), a negative feedback reduces the production rate by 20 % (to \(4\ \mu\text{g day}^{-1}\)). Ovulation occurs when the concentration reaches \(38\ \mu\text{g}\). How many days after the start of the cycle will ovulation occur?

Answer Options

A. Approximately \(22\ \text{days}\) (more precisely \(22.7\ \text{days}\)).
B. Approximately \(20\ \text{days}\) (more precisely \(20.1\ \text{days}\)).
C. Approximately \(30\ \text{days}\) (more precisely \(30.4\ \text{days}\)).
Correct Answer D. Approximately \(25\ \text{days}\) (more precisely \(25.3\ \text{days}\)).
Correct Answer
D
Correct Option:
Approximately \(25\ \text{days}\) (more precisely \(25.3\ \text{days}\)).

About This Question

This is Gce Model Questions Vol1 2025 Biology Question 23. It is one of the objective questions from the 2025 Gce Model Questions Vol1 Biology examination.

Difficulty level: Medium .

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