Biology in action – molecular biology, biological control, and human ecology
BiologyEcology & EnvironmentAges 17–18
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Sign in to playThree biology topics in one simulation, selected with the topic parameter. Molecular biology: run a PCR reaction through the denaturation 95 °C – annealing 55 °C – extension 72 °C cycle, with the number of DNA copies rising as 2ⁿ and showing up on a gel. Biological control: release natural predators into a field to keep pests in check, compared with spraying pesticide once pests become resistant. Human ecology: choose a lifestyle for diet, travel, and electricity use to calculate the ecological footprint in global hectares and the number of Earths it would take.
Lesson: Molecular biology (PCR technique); biological control using natural predators; human ecology and the ecological footprint
What it shows
Three applied topics share one screen. PCR amplifies a chosen DNA segment by cycling through denaturation at 95 °C, primer annealing at 55 °C and extension at 72 °C with heat-stable Taq polymerase; in theory each cycle doubles the copies, giving 2ⁿ after n cycles. Biological control models a predator–prey system in which released predators hold pests below the damage level, while repeated spraying selects for resistant pests. The ecological footprint converts diet, travel and other consumption into global hectares and compares the total with Earth's biocapacity per person.
How to use
Switch topics with the three tabs. In PCR, press One PCR cycle repeatedly and predict the copy number before each step, then let it run to the set Number of PCR cycles. In Biological control, drag to change how many predators are released and compare the oscillating curves with Spray pesticide. In Ecological footprint, press Change diet and drag sideways to change the daily travel distance, noting how many Earths the lifestyle would need.
Parameters you can change
- Current topic 1. Molecular biology: PCR technique, 2. Biological control using natural predators, 3. Human ecology: ecological footprint
- Number of PCR cycles 1–35 cycles
- Natural predators released into the field 0–50 individuals/100 m²
- Spray pesticide instead of natural predators
- Daily diet High red meat, Balanced meat and vegetables, Mostly plant-based
- Daily distance traveled by motorbike or car 0–80 km
Questions to explore
- Starting from one DNA molecule, how many copies does PCR produce in theory after 10 cycles?
- Why can repeated pesticide spraying lead to a stronger pest outbreak than using natural predators?
- Which change in diet or daily travel reduces the ecological footprint the most in the simulation?
