Applied biology – mineral nutrition, human epidemics, and food safety
BiologyHealth & DiseaseAges 16–17
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Sign in to playThree applied-biology topics in one simulation, selected with the topic parameter. Mineral nutrition: choose the deficient element and the supply level to see leaf symptoms, plant height, and yield change. Human epidemics: an SIR model with a transmission rate R₀ and a vaccination rate, showing daily case counts and the herd-immunity threshold. Food safety: bacteria in food doubling with storage temperature, calculating the time to reach the infectious dose of 10⁶ CFU/g.
Lesson: Mineral nutrition, raising crop yield, and clean agriculture; human epidemics and prevention; food hygiene and safety
What it shows
Three quantitative models are grouped here. Mineral nutrition applies the law of the limiting factor: the scarcest nutrient caps growth and yield, and nitrogen, phosphorus and potassium deficiencies each give distinctive leaf symptoms. The epidemic model is an SIR model with a 7-day infectious period, in which vaccinating more than 1 − 1/R₀ of the population stops an outbreak from spreading. Food safety models exponential bacterial growth, N = N₀·2^(t/g), with a generation time that shortens in the 5–60 °C danger zone and becomes very long near fridge temperature.
How to use
Switch topics with the three tabs. In Mineral nutrition, drag sideways to change the supply level and press Change deficient element to compare leaf symptoms and yield. In Epidemics (SIR), drag to set R₀, then press Increase vaccination +20% until the outbreak no longer takes off. In Food safety, drag to set the storage temperature and read how long bacteria take to reach the infectious dose, then press Put in fridge at 4 °C and compare.
Parameters you can change
- Current topic 1. Mineral nutrition and yield, 2. Human epidemics (SIR model), 3. Food hygiene and safety
- Deficient mineral element Sufficient nutrients, Nitrogen deficiency (N), Phosphorus deficiency (P), Potassium deficiency (K)
- Mineral supply relative to demand 0–150 %
- Basic reproduction number R₀ 0.5–15
- Share of population vaccinated 0–100 %
- Food storage temperature -5–45 °C
Questions to explore
- With R₀ = 4, what minimum share of the population must be vaccinated to prevent an outbreak?
- How do the leaf symptoms of nitrogen deficiency differ from those of potassium deficiency?
- How long does food take to reach the infectious dose at 30 °C compared with 4 °C?
