11.5 Calculating Genetic Biodiversity Flashcards
What is the importance of genetic biodiversity?
greater genetic biodiversity = more alleles
some organisms carry advantageous allele
∴ more resistant to changes in environment
species less likely to become extinct due to change in environment
Which factors increase genetic biodiversity?
(factors which increase number of alleles in a population)
- MUTATION
- INTERBREEDING
- breeding of individuals from different populations transfers alleles - gene flow
Which factors decrease genetic biodiversity?
(factors which decrease number of alleles in a population)
- SELECTIVE BREEDING/ARTIFICIAL SELECTION
- only individuals with advantageous alleles chosen & bred
- NATURAL SELECTION
- over time, species evolve to contain mostly advantageous alleles, less advantageous alleles die out/only present in few individuals.
- GENETIC BOTTLENECKS
- event wipes out large proportion of population, reduces gene pool.
- FOUNDER EFFECT
- population created by only few individuals, so gene pool is small
- GENETIC DRIFT
- random nature of inheritance of alleles, some alleles disappear from population by chance.
- ARTIFICIAL CLONING/ASEXUAL REPRODUCTION
- clones have virtually identical DNA, ∴ no introduction of new alleles by reproduction
- CAPTIVE BREEDING PROGRAMMES
- population arises from small number of captive individuals, ∴ small gene pool
In what way can you measure genetic biodiversity?
measuring polymorphism
What is a polymorphic gene?
gene with multiple alleles
What are examples of polymorphic genes?
blood type, eye colour etc
What is the formula for the proportion of polymorphic gene loci?
number of polymorphic gene loci / number of gene loci
What are monomorphic genes?
a gene for which only 1 allele exists
The greater the proportion of _____ gene loci within a species, the greater the genetic biodiversity of the species.
polymorphic
