(todo 9.11B) Ecosystems and Biodiversity - Paper 2 Flashcards
(17 cards)
Define organism
Define population
Define community
Define ecosystem
List abiotic factors affecting communities.
todo explain how
- Light intensity
- Temperature
- Moisture levels
- Soil pH content
- Soil mineral content
- Wind intensity and direction
- Carbon dioxide levels for plants
- Oxygen levels for aquatic animals
- Levels of pollutants
List biotic factors affecting communities.
todo explain how
- New predators
- New pathogens
- Competition for food
- Competition for mates
- Competition for territory
Describe parasitism, with examples.
Parasites live inside another ‘host’ organism, taking what it needs without the host receiving anything in return.
Fleas live on dogs and feed on their blood - gaining food and a habitat.
Tapeworms live inside the small intestine of their hosts, absorbing digested products.
Describe mutualism, with examples.
Mutualism is a relationship between two species where both species benefit.
Bees obtain nectar for food and spread pollen between flowers, aiding plant reproduction.
Small cleaner fish gain nutrition and protection by eating the parasites around the gills of much larger fish.
Lichens are formed by fungi providing shelter for algae that photosynthesises to make food for both.
How wide is a standard quadrat?
50cm
How is the length of a food chain limited?
At each tropic level energy is transferred to less useful forms.
This determines the shape of a pyramid of biomass.
Which human activities can negatively impact biodiversity?
- Overuse of fertilisers
- Fish farming
- Introduction of non-indigenous species
How can overuse of fertilisers negatively impact biodiversity?
How can fish farming negatively impact biodiversity?
How can introduction of non-indigenous species negatively impact biodiversity?
How can human activities positively impact biodiversity?
- Breeding programs to help preserve endangered species
- Protection and development of new endangered habitats
- Replanting hedgerows (more biodiverse than the fields they surround)
- Reforestation and reducing deforestation
- Reducing greenhouse gas emissions
- Recycling
How is the future of humanity dependent on maintaining global biodiversity?
We rely on many different species as food or sources of medicine so it is important to the health of future generations that organisms that supply us with these resources are not lost.
Why is maintaining local biodiversity important?
Habitats and ecosystems with high biodiversity are attractive places to visit for recreation and tourism, benefitting and providing income to local people.
