Environmental data lab
Thu, Apr 8, 2027 · Week 12 · Biotechnology for Health (Biomedical Innovations)
Today's goal: Culture a coded mock water sample on LB agar with sterile technique, so that next class you can say whether it holds bacteria and how many.
This is a model of the work you should turn in today. Use it to check your own: match the structure and the level of detail, do not copy it. Your data and wording should be your own.
Dataset: city drinking-water lead samples (units: parts per billion, ppb).
Measured values: 8, 12, 15, 22, 9 ppb. Average = 13.2 ppb.
Published threshold: EPA lead action level is 15 ppb.
Comparison: The average (13.2) is below 15 ppb, but two individual samples (15 and 22 ppb) meet or exceed the action level, so some homes are over the limit.
Dose estimate: For a 20 kg child drinking 1 liter/day at 22 ppb: 22 micrograms/L times 1 L = 22 micrograms/day, divided by 20 kg = about 1.1 micrograms per kg per day.
Bioaccumulation flag: Flagged. Lead accumulates in bone over time and is eliminated slowly, so repeated daily intake builds up rather than clearing, which raises long-term risk even at concentrations near the threshold.
| Sample | Lead (ppb) | Over 15 ppb action level? |
|---|---|---|
| 1 | 8 | No |
| 2 | 12 | No |
| 3 | 15 | At limit |
| 4 | 22 | Yes |
| 5 | 9 | No |
This model shows the level of evidence and organization needed to complete: Completes the Problem 4 data lab: a dataset analysis comparing measured pollutant concentrations to a published safe threshold, a dose estimate, and a bioaccumulation flag.
- Name the variables and include units.
- Enter observations without changing the raw values.
- Check labels, calculations, and patterns before interpreting the data.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Also due today: Submit your completed data table and written conclusion on Schoology.
Turn in: Culturing record: your coded sample letter, the dilution scheme (1/10, 1/100 and 1/1,000), the volume plated (0.1 mL), the label on every plate, a completed sterile-technique checklist, your prediction of which dilution will give 30 to 300 colonies with the arithmetic behind it, and both controls named. Results stay pending until the plates are read on April 9.
Go to Schoology to turn this in.
Submit one PDF. Schoology attaches your name to your upload; on the page itself, write your period and code. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf.
Open Schoology PDF upload helpIf you cannot get in, see Mr. Mendoza. Do not skip the work.
Claim ceiling: A classroom culture of a teacher-prepared E. coli K-12 sample shows whether bacteria grew on LB agar under these conditions. It cannot test real drinking water, identify coliforms or E. coli, or judge any water safe or unsafe.
One exam-style question that uses exactly what you practiced today. Try it before you reveal the answer, then read why each choice is right or wrong.
Tap an answer to see the full explanation. Nothing is recorded or graded.
It builds this reusable test skill: Comparing measured values to a safety threshold and reading bioaccumulation.
- Name the concept or data pattern being tested.
- Cross out choices that violate that rule or the evidence.
- Justify the best remaining choice before checking the answer.