Investigating Populations Flashcards
Define biodiversity
The number of species and the number of individuals of each species
Define species richness
The number of different species in a community
Define community
All the individuals of all the species living together in an area at the same time
Define species
A group of similar organisms that are able to reproduce to produce fertile offspring
What is ecology
The study of organisms and the environment they interact with and live in and with one another
Define genetic diversity
Difference in DNA/base sequence/alleles/genes
Define niche
An organisms role in its community/ecosystem
It describes what a species is like, where it occurs and how it interacts with other species or responds to the environment (the food it eats)
No two species share the same ecological niche due to the competitive exclusion principle
Define habitat
A place in which an organism normally lives within an ecosystem, characterised by biotic and abiotic factors
What is a diversity index and what is the formula
A measure of the number of species present in an area and the relative abundance of each species
Always greater than one
N(N-1)/Σn(n-1)
N=Total number of organisms of all species
n=Total number of organisms of each species
Why is index of biodiversity more useful than species richness
Index of biodiversity also measures the number of individuals in a species
Same species may be present in high or low numbers
Advantages of using index of diversity instead of indicator species
You don’t need to identify each species
Index considers the number of organisms of each species
What does a higher diversity mean for the environment
More stable the ecosystem is and so less likely a disease or climate change will affect every organism
Ecosystem continues to exist after disasters
What does a lower diversity mean for the environment
Less stable the ecosystem is and so if a few organisms were to die it would have a severe affect on the ecosystem
Less likely to survive or recover from disease, disaster or climate change
Economic arguments for maintaining biodiversity
Medical/pharmaceutical products can be obtained from living organisms Commercial uses like sheep for wool Tourism Agriculture Saving local forest communities
How can you ensure index of diversity is representative of the habitat
Random sample
Large sample
Continue sampling until you get a running mean
