Biodiversity Flashcards
Define biodiversity
a measure of the number of species and the number of individuals in a specific region
What is species richness
the number of different species in a specific region
What does high biodiversity grant the ecosystem
High stability
Why does high biodiversity make an environment stable
It provides a large enough breeding population to withstand changes to the environment. It also increases the potential for natural selection, hybridisation, evolution and survival
Name environments with high biodiversity
Oak woodlands and tropical rainforests
Name environments with low biodiversity
Deserts, arctic
What is the general trend in biodiversity from the poles to the equator
Increases
Why do tropical rainforests have high biodiversity
Plenty of light for many hours, plentiful rain, warm environment, fast nutrient recycling, huge competition
What is polymorphism
where there are two or more alleles of a gene
What is genetic polymorphism
the occurrence of more than one phenotype in a population, not caused by mutation alone
What are polymorphic loci
More than one possible allele for a gene at the locus
Name four threats to biodiversity
Loss of habitats
Over harvesting of biotic resources
pollution
alien species
What is natural selection
Individuals with advantageous genes survive and reproduce, passing their advantageous genes along the line
What is selective predation
Leads to wide changes in biodiversity eg, using DDT to kill mosquitoes
What is adaptation
Organisms are adapted to their environments showing anatomical, physiological and behavioral adaptations
