Question

A microbiologist is comparing the growth rates of two different yeast strains. She indirectly measures the number of yeast cells by recording the optical density $\left(OD600\right)$ of each strain every ten hours. Based on the data, which of the following is NOT a true statement?

• A. Strain 1 had a higher $OD600$ reading than Strain 2 throughout the monitored period.
• B. The growth rate of Strain 2 was less than the growth rate of Strain 1 until hour $50$, at which point Strain 1's growth rate became the lesser one.
• C. Between hours $50$ and $70$, Strain 2's $OD600$ reading increased by approximately $0.03$ every hour.
• D. The growth rate of Strain 1 was greater than the growth rate of Strain 2 throughout the mentioned period.

Answer 1

Answer: (D)

The growth rate of Strain 1 was greater than the growth rate of Strain 2 throughout the mentioned period.

Though the, the graph shows higher $OD600$ in strain 1 as compared to strain 2 but the growth rate is different in each interval.

Hence, options A, B, C are correct statements.

The growth rate for strain 1 was only higher between 30 to 50 hours.

Hence, option D is not a true statement.