Essential Knowledge 2.D.1

All biological systems from cells and organisms to populations, communities and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.

Cell activities are affected by interactions with biotic and abiotic factors.

Examples:

• cell density
• biofilms
• temperature
• water availability
• sunlight

Organism activities are affected by interactions with biotic and abiotic factors.

Examples:

• symbiosis (mutualism, commensalism, parasitism)
• predator-prey relationships
• water and nutrient availability, temperature, salinity, pH

The stability of populations, communities and ecosystems is affected by interactions with biotic and abiotic factors.

Examples:

• water and nutrient availability
• availability of nesting materials and sites
• food chains and food webs
• species diversity
• population density
• algal blooms

Students should be able to:

LO 2.22 Refine scientific models and questions about the effect of complex biotic and abiotic interactions on all biological systems, from cells and organisms to populations, communities and ecosystems.

LO 2.23 Design a plan for collecting data to show that all biological systems (cells, organisms, populations, communities and ecosystems) are affected by complex biotic and abiotic interactions.

LO 2.24 Analyze data to identify possible patters and relationships between a biotic and abiotic factor and a biological system (cells, organisms, populations, communities or ecosystems).