B1.5 Energy and Biomass in Food Chains Flashcards
What does a food chain show?
What eats what
What are the first 3 organisms called in a food chain?
1: Producer, 2: Primary consumer, 3: Secondary consumer
What is each stage in a food chain called and what changes?
Each stage is called a trophic level, there’s less energy and less biomass every time you move up a trophic level
What does a pyramid of biomass show?
Each bar shows the mass of living material at that stage of the food chain
What does the first 3 bars on a pyramid of biomass represent?
1: Producer, 2: Primary consumer, 3: Secondary consumer
How do you construct a pyramid of biomass? (4)
The order of the bars must follow the food chain’s order, each bar must be labelled, the bars must decrease and be drawn to scale, and the number of bars must match the number of organisms in the Q
What doesn’t a pyramid of biomass represent?
The number of organisms, e.g. there may be a bigger bar for trees than aphids, but this is only due to the tree being larger
How does energy get into a food chain?
Light energy is converted to chemical energy in plants when they photosynthesise, this energy is then stored and passed on when the plant is eaten
Why is biomass and energy lost in a food chain?
Respiration - the energy released by respiration is eventually lost to the surroundings as heat
Uneaten material - some parts of the animal is inedible e.g. bones + some animals die before they’re eaten so they decay and lose the energy to microorganisms
Waste products - material and energy is lost through faeces and urine (which are not eaten)
What is the link between energy lost and the number of trophic levels in a food chain?
The loss of energy at each state is so large that there’s not enough left to support more organisms after four/five stages
