The Variety of Life Flashcards
(33 cards)
define allele
Different versions of the same gene
define Biodiversity
A measure of the variety of life within an area
define Species Diversity
no. of different species in a particular area and their relative abundance
(A measure of species richness and species evenness)
define species richness
no. different species in a particular area
define species evenness
relative abundance of the species in a particular area
define Genetic Diversity
A measure of the number of different alleles of genes within a population
define Ecosystem
All the living and non-living components of a particular area
define Community
All the different living organisms within an ecosystem
define Habitat
The area inhabited by a particular species
define Niche
The role of a species within it’s habitat
define Population
A group of the same species living in the same area
define Endemic
found in only one geographical location (at particularly risk of extinction)
define Speciation
The development of a new species from a pre-existing species overtime
define Gene flow
The exchange of genes via interbreeding
define Gene Pool
All the different alleles, of all the different genes of all the individuals within a population
2 ways in which biodiversity can be measured
- by measuring species diversity
- by measuring genetic diversity
Why is Biodiversity important?
It allows ecosystems to resist changes in the environment
5 reasons why a species number might decrease
- endangerment
- natural disaster
- disease
- predation
- human activity
4 reasons why a species number might increase
- random mutation leading to speciation
- geographical isolation leading to speciation
- reproductive isolation leading to speciation
- evolution leading to speciation
3 ways species diversity can be measured
- via species richness
- via Species evenness/ distribution/ relative abundance
- using Index of diversity {D = N(N-1) / ∑ n(n-1)} TAKES INTO ACCOUNT BOTH SPECIES RICHNESS AND EVENNESS
how is species richness measured?
count the total number of different of species within an area {can be estimated using a quadrat}
how is species evenness/ distribution/ relative abundance measured?
count number of individuals within each species {can be estimated using a quadrat}
2 “synonyms” for species evenness
- distribution of species
- relative abundance of species
Why are Ecosystems with high species diversity usuallymore stablethan those with lower species diversity?
Because they are more resilient to environmental changes
