B2.2 Pyramids Flashcards
What do ecological pyramids represent in ecosystems?
the relative numbers, biomass, or energy of trophic levels in an ecosystem.
What do pyramids of number and biomass show?
the standing crop per unit area at a specific time.
What do pyramids of energy display, and how are they measured?
Pyramids of energy display the energy flow to each trophic level per unit area and time, usually measured in kJ m⁻² year⁻¹.
What is bioaccumulation, and how does it occur?
the increasing concentration of non-biodegradable pollutants in organisms or trophic levels over time as more pollutants are absorbed.
What is biomagnification, and how does it affect food chains?
Biomagnification is the increasing concentration of non-biodegradable pollutants along a food chain due to the loss of biodegradable biomass, such as during cellular respiration.
How do microplastics contribute to pollution in food chains?
Microplastics absorb non-biodegradable pollutants, increasing their transmission and accumulation in the food chain.
Can you give an example of pollution by microplastics and its effect on the food chain?
Microplastics in oceans are consumed by small marine organisms, leading to bioaccumulation and biomagnification of toxins like mercury as these organisms are eaten by predators higher in the food chain.
How do human activities like burning fossil fuels impact energy flows in ecosystems?
Burning fossil fuels increases CO₂, which may boost photosynthesis, but other pollutants and global warming reduce primary productivity and disrupt ecosystems.
What are the impacts of deforestation, urbanization, and agriculture on ecosystems?
lead to loss of ecosystem biomass, disruption of food webs, and reduced photosynthetic capacity.
Common examples of non-biodegradable/persistent chemicals and their uses
Mercury: Used to purify gold from ores.
PCBs (polychlorinated biphenyls): Used as coolants for engines and other heat transfer systems, manufactured from the oil industry.
DDT: An insecticide used to manage mosquito populations in tropical countries.
