Genetic biodiversity
- Created by: CalsieT
- Created on: 02-05-16 11:49
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- genetic biodiversity
- factors affecting genetic biodiversity
- decrease genetic biodiversity by decreasing no. of possible alleles
- GENETIC BOTTLENECK few individuals survive event/change (disease, enviro change, habitat destruction)
- reduces gene pool as only alleles of surviving members available to be passed on to offspring
- SELCETIVE BREEDING adavntageous characteristics selected to breed e.g. food crops + pedigrees
- CAPTIVE BREEDING PROGRAMMES zoos + conservation centres only small no. of individuals available for breeding
- often wild pop. endangered/extinct
- RARE BREEDS selective breeding used to produce domestic breed
- no.'s fall when characteristics become unfashionable, leaving small no. for breeding
- ARTIFICIAL CLONING asexual reproduction e.g. cuttings to clone farmed plants
- NATURAL SELECTION species evolve to primarily contain alleles coding for advantageous characteristics
- over time alleles coding for less advantageous characteristics will be lost/ only remain in few individuals
- GENETIC DRIFT existence of an allele disappears from pop. due to random nature of alleles passed from parents
- GENETIC BOTTLENECK few individuals survive event/change (disease, enviro change, habitat destruction)
- increase genetic biodiversity by increasing no. of possible alleles
- decrease genetic biodiversity by decreasing no. of possible alleles
- The variety of genes that make up a species (aka gene pool)
- All members of species share same genes, but different alleles create genetic biodiversity within species or population of the species
- increased genetic biodiversity = able to adapt to changes in environment, so less likely to become extinct
- some organisms that carry advantageous allele, enabling survival e.g. resistance to disease
- measuring genetic biodiversity
- proportion of polymorphic gene loci = no. polymorphic gene loci / total no. loci
- greater proportion of polymorphic gene loci = greater genetic biodiversity
- polymorphic genes = 2 or more alleles
- e.g. immunoglobulin determines human blood type has 3 alleles
- proportion of polymorphic gene loci = no. polymorphic gene loci / total no. loci
- factors affecting genetic biodiversity
- FOUNDER EFFECT small no. individuals create new colony geographically isolated from original
- small gene pool for new pop.
- decrease genetic biodiversity by decreasing no. of possible alleles
- GENETIC BOTTLENECK few individuals survive event/change (disease, enviro change, habitat destruction)
- reduces gene pool as only alleles of surviving members available to be passed on to offspring
- SELCETIVE BREEDING adavntageous characteristics selected to breed e.g. food crops + pedigrees
- CAPTIVE BREEDING PROGRAMMES zoos + conservation centres only small no. of individuals available for breeding
- often wild pop. endangered/extinct
- RARE BREEDS selective breeding used to produce domestic breed
- no.'s fall when characteristics become unfashionable, leaving small no. for breeding
- ARTIFICIAL CLONING asexual reproduction e.g. cuttings to clone farmed plants
- NATURAL SELECTION species evolve to primarily contain alleles coding for advantageous characteristics
- over time alleles coding for less advantageous characteristics will be lost/ only remain in few individuals
- GENETIC DRIFT existence of an allele disappears from pop. due to random nature of alleles passed from parents
- GENETIC BOTTLENECK few individuals survive event/change (disease, enviro change, habitat destruction)
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