Gce Model Questions Vol1 2021 Biology Question 12

Practice objective / multiple choice question 12 from the 2021 Gce Model Questions Vol1 Biology examination.

Gce Model Questions Vol1 2021 Biology Objective / Multiple Choice Hard Difficulty
Question 12 GCE_MODEL_QUESTIONS_VOL1 • 2021 • BIOLOGY • objective

In a bacterial culture, the cell density rises from \(2.0 \times 10^{6}\) CFU ml\(^{-1}\) at time 0 to \(1.6 \times 10^{8}\) CFU ml\(^{-1}\) after 4 h, assuming exponential growth. (a) Determine the generation time in minutes (to the nearest minute). (b) An antibiotic is added that reduces the growth‑rate constant by 30 % for the next 6 h. What will be the bacterial density after those 6 h? Express your answer in scientific notation with two significant figures.

Answer Options

A. Generation time = 30 min; final density ≈ 3.4×10^{9} CFU ml^{-1}
B. Generation time = 50 min; final density ≈ 2.0×10^{10} CFU ml^{-1}
Correct Answer C. Generation time = 38 min; final density ≈ 1.6×10^{10} CFU ml^{-1}
D. Generation time = 45 min; final density ≈ 1.1×10^{11} CFU ml^{-1}
Correct Answer
C
Correct Option:
Generation time = 38 min; final density ≈ 1.6×10^{10} CFU ml^{-1}

About This Question

This is Gce Model Questions Vol1 2021 Biology Question 12. It is one of the objective questions from the 2021 Gce Model Questions Vol1 Biology examination.

Difficulty level: Hard .

View More Gce Model Questions Vol1 2021 Biology Questions More Gce Model Questions Vol1 Practice Questions Back to Questions

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Chat with Support