Waec Model Questions Vol1 2021 Biology Question 13

Practice objective / multiple choice question 13 from the 2021 Waec Model Questions Vol1 Biology examination.

Waec Model Questions Vol1 2021 Biology Objective / Multiple Choice Hard Difficulty
Question 13 WAEC_MODEL_QUESTIONS_VOL1 • 2021 • BIOLOGY • objective

A culture of *Escherichia coli* starts with 5 × 10⁴ cells. During the exponential phase the population doubles every 20 min. After exactly 2 h an antibiotic is added that reduces the growth rate by 30 % (i.e., the doubling time increases by 30 %). Assuming the reduced rate continues, how many cells will be present after a total of 5 h from the start of the culture? Give your answer in scientific notation to two significant figures.

Answer Options

A. 2.6×10⁸ cells
Correct Answer B. 3.9×10⁸ cells
C. 1.2×10⁹ cells
D. 5.1×10⁸ cells
Correct Answer
B
Correct Option:
3.9×10⁸ cells

About This Question

This is Waec Model Questions Vol1 2021 Biology Question 13. It is a objective / multiple choice question from the 2021 Waec Model Questions Vol1 Biology examination.

Difficulty level: Hard .

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