Energy Transfer In Ecosystems Flashcards
1
Q
What is an ecosystem?
A
- All the organisms living in a particular area and all the abiotic conditions.
2
Q
What are producers?
A
- Organisms that make their own food.
- E.g. plants and algae produce their own food through photosynthesis.
3
Q
What is biomass?
A
- Chemical energy stored.
4
Q
How can biomass be measured?
A
- Using a calorimeter.
5
Q
How is biomass measured using a calorimeter?
A
- Sample of organism is dried, in an oven set to a low temp. Sample is weighed at regular intervals. Once mass becomes constant, all water has been removed.
- (If needed) result from the sample can be scaled up to give the biomass of the total pop. or the area being investigated.
- The mass of carbon present is generally taken to be 50% of the dry mass.
6
Q
How can you estimate the chemical energy stored in biomass?
A
- Burn the dry biomass and any energy released is used to heat a known volume of water.
- The change in temp. is used to calculate chemical energy of dry biomass.
7
Q
What is gross primary production (GPP)?
A
- The total amount of chemical energy converted from light energy by plants, in a given area.
8
Q
What is net primary production (NPP)?
A
- The energy available to the plant for growth and reproduction.
- It is also the energy available to organisms at the next stage in the food chain.
9
Q
What is the calculation for net primary production (NPP)?
A
net primary production = gross primary production - respiratory loss
10
Q
How do consumers store chemical energy?
A
- In their biomass
11
Q
How do consumers get energy?
A
- By ingesting plant material, or animals that have eaten plant material.
