Life On Earth pt2 Flashcards
Biome
A large region of the earth that can be distinguished from other biomes by the abiotic factors that affect it, e.g. Climate and the particular fauna and flora it possesses
Competition
The interaction between organisms requiring the same resources
Primary consumer
The first organism that eats the producer, second in a food chain
What would happen to the producer if the primary consumer where to die out?
They would increase
Pyramid of numbers
Shows the relative numbers of each organism in a food chain
What dose a light meter measure
Light intensity
To minimise errors when sampling light in an area we would….
Take multiple readings at the same time of day and make sure no shadow is cast on the meter
What is temperature measured by
A thermometer
To minimise errors when using a thermometer we…
Allow the reading to stabilise and if using a soil thermometer wipe the probe clean between readings
What do we use to measure PH
A PH meter
To minimise errors when sampling PH we can
Wipe the probe clean between readings
Mutations
Random and spontaneous change in genetic material
Mutagenic agents
can cause an increase in mutation rate e.g. Radiation ( X-rays, gamma rays , UV rays), chemicals
Natural selection
Allows the best adapted organisms to survive and pass their favourable genes to future generations
Speciation
Occurs after a population has become isolated by an isolation barrier.these can be geographical, ecological or reproductive barriers
How do pesticides affect food chains
When pesticides are sprayed onto crops toxicity can build up and accumulate in the bodies of organisms higher up in the food chain e.g. The organism higher up in the food chain will have the highest toxicity level
Name an alternative to pesticides
Biological control e.g. Adding lady birds to get rid of green flies
Interspecific competition
between member of a different species for similar resources
Infraspecific competition
Between members of the same species for the same resources
