B18 - Biodiversity and Ecosystems Flashcards
What is Biodiversity?
The variety of different species of organisms within our ecosystem.
Why is high biodiversity important?
It makes sure that ecosystems are stable
What are three human actions that reduce biodiversity?
Land fill
Deforestation
Combustion of fossil fuels
Why has the population of the world been increasing since the mid 1800s?
Modern medicine and farming reduce deaths from disease and hunger
How does pollution decrease biodiversity?
Its kills plants and animals
How can waste become polluted?
Sewage and toxic chemicals from farming
How can land become polluted?
Toxic chemicals from farming
Landfill sites
How can air become polluted?
Release of Smoke and acidic gases
What are trophic levels?
The different levels of a food chain
What is at Trophic level 1?
Always a producer
Where does all the energy from the entire food chain come from?
The producers that photosynthesise to produce glucose
Who is at Trophic level 2?
Primary consumers - herbivores
Who is at Trophic level 3?
Secondary consumers - also known as carnivores/predators
What is every level after trophic level 2, called?
Carnivores/predators
Why do food chains usually stop at trophic level 4-5?
As you go up trophic levels, the energy from the producers get lost
What do pyramids of biomass show?
The biomass of each trophic level in a food chain
What does biomass mean?
The mass of living organisms
In pyramids of biomass, as you go up, the bars gets smaller.
What does this mean?
The total mass of the organisms in each level are decreasing
What is the 10% idea in pyramids of biomass?
Only 10% of the energy is passed on. And with that 10%, only 10% is passed on. This repeats
Why does the 10% idea in pyramids of biomass exist?
- Organisms don’t normally eat every part of other organsims
- Indigestible body parts like teeth or scales aren’t used and just come out in faeces
- Most of the nutrients animals do absorb is used to release energy through respiration - not for growth
How do you calculate the efficiency of biomass transfer?
((Biomass in the next level / biomass in previous leve)) x 100
