topic 4 Flashcards
species diversity
the number of different species and the abundance of each species in an area.
genetic diversity
- the variation of alleles within a species.
species richness
- the number of different species in the area (the higher the number of species the higher the species richness)
heterozygosity index
the heterozygosity index measure the genetic diversity
h = number of heterozygotes/ number of individuals in the population
index diversity
- how to measure the species diversity
d = N(N-1)/ sum of n(n-1)
N= total number of ALL species n = total number of ONE species
- the higher the number the more diverse
niche
- the role of an organism in its habitat
echa species has its own unique niche, if two species have the same niche, one will out compete the other, then the other will die.
how organism can be adapted
- behavioural
- physiological
- anatomical
adaptations are more common.
mutations introduce new alleles into the population
selection pressures will create a struggle to survive
individuals with the advantageous allele will survive and will pass on the advantageous allele, increasing the frequency of the advantageous allele.
speciation in the devlopment of a new species
the species are geographically isolated
the conditions on each side of the barrier are different
different characteristics will be better suited for the climate
and there are different selection pressures and then those with the better allele will survive and will increase the frequency of that allele will increase
as well as mutations occuring where the advantagous mutation will survive
then they become genetically distinct, and can no longer produce fertile offspring
if any changes such as mutations occur, they can no longer
hardy weinberg
-predicts thst the frequencies of alleles in a population wont change from one generation to the next
how can biodiversity be conserved
- zoos ( captive breeding programmes)
- seed banks
conservation of biodiversity (zoos)
- captive breeding programmes involve breeding animals in controlled environments
- species that are endangered will be kept in the zoo to breed together to increase their numbers
HOWEVER…
- some people think it is cruel to keep animals in captivity
- many animals may have problems breeding outside of their homes which is hard to replicate in zoos
conservation of biodiversity (seed banks)
- store a lot of seeds from different species of plants
- help conserve biodiversity by storing the seeds of endangered plants
- if the plant is extinct in the wild the stored seeds can be used to grow new plants
- they help conserve the genetic diversity, because they have a range of seeds with different characteristics and therefore different alleles,
what is the correct environment for a seedbank
- create a cool, dry environment (when storing)
- testing the seeds for viabilities (the ability to grow into a plant)
- the seeds are planted, grown and then new seeds are harvested to put back into storage.
what are the advantages and disadvantages of seed banks
advantages
- cheaper to store seeds than plants
- large number of seeds can be stored
- less labour (less work is needed to keep the seeds)
- the seeds can be stored anywhere as long as conditions are correct
- the seeds are less likely to be damaged by disease, natural disaster, or any type of vandalism.
disadvantages
- the testing for the viability of the plants can be expensive and time consuming
- it is difficult to collect seeds from plants as they may grow in very remote areas
