Description
An algal bloom scenario serves as the investigative phenomenon that students are tasked with explaining. To make sense of the phenomenon, students investigate growth in algae populations maintained in different concentrations of nutrient solution. Over the course of the investigation, students conduct experiments and analyze data to answer the driving question, “What effect will different nutrient concentrations have on the carrying capacity of algal populations?”
Time Requirement
Teacher prep before each component of the lab, 20 to 30 minutes (a total of approximately 100 minutes). Pre-lab, investigation 1, investigation 2 setup, and analysis, approximately 50 minutes each. Note: Investigation 2 requires 5 minutes of data collection 3 times a week for 3 weeks.
Digital Resources
Includes 1-year access to digital resources that support 3-dimensional instruction for NGSS. Digital resources may include a teacher manual and student guide, pre-lab activities and setup videos, phenomenon videos, simulations, and post-lab analysis and assessments.
Crosscutting Concepts
Systems and System Models
Scale, Proportion, and Quantity
Science and Engineering Practices
Using Mathematics and Computational Thinking
Learning Objectives
- Collect algal population density data over time and use a modified logistic growth model to determine the intrinsic population growth rate and carrying capacity.
- Describe the differences between exponential growth and logistic growth and argue from evidence that algal population growth is density dependent.
- Use the mathematical model to predict population size at any given time and compare the prediction with experimental results.
- Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales.
- Use evidence to identify the factors that have the largest effect on the carrying capacity of an in vitro algal population.
- Use mathematical reasoning to interpret population growth models and graphs from collected data.
Prerequisite Knowledge and Skills
Students should know why energy is important to living things. They should have a basic understanding of the energy dynamics of photosynthesis and cellular respiration; and have a degree of familiarity with food chains and common components of a biological community in aquatic ecosystems.