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Science · Drill 78

Science practice 78

6 questions ~9 min recommended
⏱ 00:00
Score
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I appreciate your question, but I need to clarify an important issue: the input you've provided appears to be **three data tables** (Table 1, Table 2, Table 3) rather than a continuous prose passage with underlined text and embedded question markers. The instructions I was given are designed for **ACT English passages** — which are narrative or expository text where: - Specific phrases are underlined in the printed test - Question numbers appear as subscripts/markers in the passage itself - Multiple-choice options suggest alternative wordings for those underlined portions **What you've provided instead:** - Raw tabular data (dish numbers, pH levels, growth percentages, compounds, temperatures) - Questions that appear to be about **interpreting experimental data** or **experimental design** (typically ACT Science Reasoning section, not English) - No underlined phrases within the tables to mark **To help you effectively, I would need:** 1. A prose passage (paragraph text) with actual underlined portions marked by standalone digits (1, 2, 3, etc.) 2. Multiple-choice answers that reference alternative phrasings for those underlined texts If you have an actual ACT English passage to convert to HTML, please provide it in that format, and I'll render it correctly. If you're working with science test materials, those require a different approach than what I'm designed to provide.

PASSAGE VII

Several scientists considered some different environmental factors and their influence on the growth of certain bacteria. The following experiments used Salmonella bacteria to measure the effect of pH levels, nutrients, and temperature on the number of bacteria produced within a given time period.

Experiment 1

A known quantity of Salmonella bacteria was placed in each of 3 Petri dishes with the same nutrient concentration at the same temperature. The pH level of each nutrient concentration in each dish was varied according to Table 1. On the pH scale, 7 represents neutral, values less than 7 indicate an acid, and values greater than 7 indicate a base. The lids of the Petri dishes were replaced after the bacteria were added and the dishes were left alone. After 6 hours, the percent growth of Salmonella bacteria was recorded (Table 1).

Experiment 2

A known quantity of Salmonella bacteria was placed in each of 3 Petri dishes with different nutrient concentrations in the form of organic compounds. The temperature and pH level (neutral 7) were held constant in each sample. The lids of the Petri dishes were replaced after the bacteria were added and the dishes were left alone. After 6 hours, the percent growth of Salmonella bacteria was recorded (Table 2).

Experiment 3

A known quantity of Salmonella bacteria was placed in each of 3 Petri dishes at different temperatures. The pH level and nutrient concentrations were held constant. The lids of the Petri dishes were replaced after the bacteria were added and the dishes were left alone. After 6 hours, the percent growth of Salmonella bacteria was recorded (Table 3).

1. According to Table 1, what might best contribute to the growth of Salmonella bacteria?

2. According to the results of the three experiments, which combination of the three factors studied would be expected to produce the highest percent growth?

3. Which of the following conclusions is strengthened by the results of Experiment 1?

4. Bacteria will generally reproduce until all of the nutrients available have been depleted. How could Experiment 2 be altered to maximize the length of time that bacteria will reproduce?

5. Which of the following was the independent variable in Experiment 3?

6. The experiments recorded the percent growth that occurred over a 6-hour period. Bacteria often reproduce at a rate that drastically varies from one stage to the next. The best way to study the different stages of growth would be to record the percent growth:

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