Biodiversity Flashcards
Biodiversity definition
the no. species + no. individuals of each species within any one community
Species richness definition
no. different species in a community
community definition
all the individuals of all the species living together in the same area at the same time
species definition
-group of similar organisms with the same genes
-reproduce to produce fertile offsprings
genetic diversity definition
-difference in DNA
-the number of different alleles of genes in a population
Niche definition
An organisms specific role in the community (how it interacts with other species, how it responds to the environment)
Habitat definition
a place where an organisms normally lives within an ecosystem
how to calculate Diversity index
draw equation
d= species diversity index
N= total no. organisms of all species
n= total no. organisms of each species
E= sum of
explain why an index of diversity may be a more useful measure of biodiversity
-measures number of individuals in a species
-some species may be present in low/high numbers
give 2 advantages of using an index of biodiversity rather than an indicator species
-you do not need to identify each species
-considers the number of organisms of each species
suggest one economic argument for maintaining biodiversity
-medical uses
-commercial products (must give examples)
-tourism
-agriculture
-saving local forest communities
relationship between diversity and stability
-the more DIVERSE an ecosystem the MORE STABLE that ecosystem is
how does farming affect diversity
-tends to reduce species diversity
-farming activities may reduce variety of food sources and habitats and niches
-growth of one species occurs while growth of another species is controlled
-pesticides and herbicides may be used to kill unwanted species
-fertilisers are used to encourage growth of specific crops
Courtship behaviour process
-organisms TO ATTRACT A MATE of the RIGHT SPECIES and RIGHT SEX, carry out courtship behaviour
-ensures reproductive success
Give two ways in which courtship increases the probability of successful mating
-attracts/recognises same species
-attracts/recognises opposite sex
-indication of sexual maturity
-stimulates release of gametes
-form a pair bond
