3.5.3 Energy and Ecosystems Flashcards
What is a trophic level?
The pattern of energy flow in a food chain
What is the basic food chain diagram?
Sun = Producers = Consumers
= Decomposers
What are the types of consumers?
Primary, secondary, tertiary… etc
Depends on the food chain in relation to the producers
Are plants the only type of producers?
No, algae and some bacteria are producers
Which way do arrows point in a food chain diagram?
Towards the consumer
What is biomass?
When sugars that aren’t used up by the plant are used to make biological molecules, these molecules from the biomass of the plant
How can biomass be measured?
In terms of mass of carbon or dry mass of tissue per given area
Can be estimated using calorimetry
What is ecology?
The study of how organisms interact with one another in their environment
What is an individual?
A single organism in a population
What is a population?
A group of individuals of the same species occupying a given area at the same time
What is a community?
All the populations living in a defined area
What is a habitat?
The area where an organism lives, including where it finds food and mates
What is a niche?
Where an organism lives and what it does there
What is an ecosystem?
A community plus all the abiotic factors
What is a biosphere?
All of the Earth’s ecosystems
What is a biome?
Large regions characterised by certain climates
What are the limiting factors in aquatic environments?
Salinity, dissolved oxygen content, light, temperature
How much of the sun’s energy do plants convert into organic molecules?
1 - 3%
Why is so little of the sun’s energy converted into organic molecules by plants?
Misses chloroplasts
Is reflected
Not all waves of light can be absorbed
CO2 becomes limiting
What is primary productivity?
The amount of new biomass of producers per unit time and space, measured in kJ/m2/year
What is gross primary production?
The total amount of energy captured
What is the equation for net primary production?
GPP - respiration
What is net primary production?
The amount of energy available to consumers and decomposers
Why doesn’t 100% of the energy from food not go into primary consumers?
Some lost in growth and reproduction
Not all of the plant is available
Some parts can not be digested
Some energy is lost in excretotry materials
Energy is needed to have a high body temperature
What is the equation for energy efficiency?
Energy available after the transfer
————————————————— X 100
Energy available before the transfer
What is the equation for net production?
N = I - ( F + R ) I = energy in ingested food F = energy in faeces R = energy in respiration
