Food Chains And Energy Transfer Flashcards
What three groups are organisms divided into according to how they obtain energy and nutrients
Producers, consumers, saprobiont
What are producers
Photosynthetic organisms that manufacture organic substances using light energy, water, carbon dioxide and mineral ions
What are consumers
Organisms that obtain their energy by feeding on other organisms rather than using the energy of sunlight directly. Animals are consumers.
What are the primary, secondary and tertiary consumers
Those that directly eat producers (green plants) are called primary consumers as they are the first in the chain of consumption
Those animals eating the primary consumers are called secondary consumers
This raging the secondary consumers are called tertiary consumers.
What are saprobionts
A group or organisms that break down the complex materials in dead organisms into simple ones.
In doing so, they release valuable minerals and elements in a form that can be absorbed by plants and so contribute to recycling.
The majority of this work is carried out by fungi and bacteria
What’s a food chain
Describes a feeding relationship in which the producers are eaten by primary consumers. These in turn are eaten by secondary consumers, which are then eaten by tertiary consumers. In long food chains this may be eaten by a quaternary consumers
What is each stage in the chain referred to
Trophic level
What do the arrows on food chain diagrams represent
The direction of energy flow
What’s a food web
Most animals do not rely on a single food source within a single habitat many food chains will be linked together to form a food web
What is biomass
The total mass of living material in a specific area at a given time
How is biomass measured
Dry mass per given area, given time
What is biomass measured in
Grams per square metre (gm^-2) when an area is been sampled
Grams per cubic metre (gm^-2) where it’s volume is been sampled
What can be used to estimate the chemical energy store in dry mass
Calorimetry
How do we carry out a bomb calorimetry
A sample of dry mass is weighed and then burnt in pure oxygen with a sealed chamber called a bomb
The bomb is surrounded by a water bath and the heat of combustion causes a small temperature rise in this water
As we know how much heat (energy) is required to raise the temp of 1g of water by 1degree, if we know the volume of water and the Temperature rise, we can calculate the energy released from the mass of burnt biomass in Units such as KJKg^-1
How does energy enter the ecosystem
Sunlight which is conserved as chemical energy by plants. Most plants use sunlight in making organic compounds from carbon dioxide in the air or water that surrounds them
