AQA A Level Biology: Biodiversity within a community Flashcards
What is biodiversity?
The variety of living organisms in an ecosystem.
What are the three levels of biodiversity?
Species diversity, genetic diversity, and ecosystem diversity.
What is species diversity?
The number of different species and the abundance of each species in a community.
What is genetic diversity?
The variety of alleles within a species or population.
What is ecosystem diversity?
The variety of habitats, communities, and ecological processes.
What is species richness?
The number of different species in a community.
What is species evenness?
The relative abundance of each species in a community.
How is species diversity measured?
Using the index of diversity (D).
What is the formula for index of diversity?
D= N(N-1)/Σn(n-1)
• N = total number of organisms of all species. • n = number of organisms of each species.
What does a high index of diversity indicate?
A more diverse and stable community.
What does a low index of diversity indicate?
A less diverse and less stable community.
What impact does agriculture have on biodiversity?
It reduces biodiversity due to monoculture, habitat destruction, and use of pesticides.
What is monoculture?
The cultivation of a single crop species over a large area, reducing biodiversity.
How does deforestation affect biodiversity?
It destroys habitats and reduces the number of species in an area.
How do pesticides affect biodiversity?
They kill insects and other organisms, reducing species diversity.
What is hedgerow removal and its impact on biodiversity?
The clearing of hedgerows to increase farmland, reducing habitats and biodiversity.
How can biodiversity be conserved in agriculture?
By maintaining hedgerows, planting wildflowers, and reducing pesticide use.
What is conservation?
The protection and management of ecosystems to maintain biodiversity.
What are the two types of conservation?
In situ (on-site) and ex situ (off-site) conservation.
What is in situ conservation?
Protecting species in their natural habitat, such as national parks and nature reserves.
What is ex situ conservation?
Protecting species by removing part of the population and breeding them in captivity, such as zoos and seed banks.
How does maintaining biodiversity benefit agriculture?
It ensures a variety of species that can contribute to pest control, pollination, and soil health.
What is the impact of climate change on biodiversity?
It alters habitats, leading to species migration, extinction, and reduced biodiversity.
What is the role of reforestation in increasing biodiversity?
It restores habitats, allowing species to recolonize and increasing biodiversity.
What is a habitat corridor and its importance?
A strip of habitat that connects isolated populations, promoting gene flow and increasing biodiversity.
What is genetic bottleneck and how does it affect biodiversity?
A reduction in population size that decreases genetic diversity and increases the risk of extinction.
How does intensive farming reduce biodiversity?
Through monoculture, pesticide use, and habitat destruction.
What is crop rotation and how does it help biodiversity?
The practice of growing different crops in succession to maintain soil fertility and support diverse organisms.
How can reducing pesticide use improve biodiversity?
It allows natural predators and other organisms to thrive, increasing species diversity.
What is sustainable agriculture?
Farming practices that protect the environment and biodiversity while producing food.
Why is maintaining biodiversity important for ecosystems?
It ensures ecosystem stability, resilience, and the provision of essential services.
