ACT Science Quiz #9

Based on Activity 1, which of the nutrient broths appears to produce the slowest doubling time for the bacteria populations? 

• Broth A

• Broth B

• Broth C

• Broth D

Answer explanation

The data in Table 1 shows that Broth C produces larger doubling times than any of the other broths. 

If the student needed to produce a very large sample of a bacteria population as quickly as possible, which bacteria species should he grow under which light? 

• E. coli under blue light

• Salmonella under blue light 

• Streptococcus under red light 

• Shigella under yellow light 

According to Activity 2, if the student began growing a population of 1,000 Salmonella bacteria under red light, he should expect to have 4,000 in how many minutes? 

• 30

• 32

• 34

• 36

If the student were to introduce a fifth bacterium into Activity 2 with a doubling time of 28 minutes in Broth D under yellow light, which of the following doubling times (in minutes) might he most likely expect the fifth bacterium to have under blue light? 

• 27

• 28

• 29

• 30

In working with the bacterial growth equation in Activity 3, the student notices a correlation between the growth constant k and the doubling time of the bacterial populations. Which of the following correlations is most likely true? 

• As k increases, doubling time increases. 

• As k increases, doubling time decreases. 

• As k increases, doubling time is unaffected. 

• There is no correlation between k and doubling time.