Calculating genetic biodiversity Flashcards
(16 cards)
Why is maintaining genetic biodiversity essential for survival of a species?
Since in isolated populations, organisms in captive breeding programmes where only few individuals are available for breeding, suffer from reduced genetic biodiversity leading to complications
Why do we measure genetic biodiversity?
To monitor the health of the population + ensure its long-term survival
What makes up genetic biodiversity?
Different alleles seen between individuals of a species
More genetic biodiversity means a species is more likely to adapt to changes in environment - because it’s likely some individuals will carry an advantageous gene
How can the number of possible alleles in the population increase for genetic biodiversity to increase?
- Mutations in DNA of organism, creating new allele
- Interbreeding between different populations. When individuals migrate from 1 population + breeds with members of another population, alleles transferred between 2 populations (known as gene flow)
How can the number of alleles in population decrease for genetic biodiversity to decrease?
- Selective breeding
- Captive breeding
- Artificial cloning
- Natural selection
- Genetic bottlenecks
- Founder effect
- Genetic drift
What is selective breeding?
Where only a few individuals within population are selected for their advantageous characteristics + are bred
What is captive breeding?
Takes place in zoos + conservation centres
Where small num of captive individuals of a species are available for breeding
What is artificial cloning?
Asexual reproduction, e.g. using cuttings to clone a farmed plant
What is natural selection?
Species evolve to only contain alleles that code for advantageous characteristics
Over time, alleles coding for less advantageous characteristics will be lost from population
What are genetic bottlenecks?
Where few individuals within a population survive an event or change, reducing gene pool
Only alleles of surviving members of population are available to be passed onto offspring
What is the founder effect?
Where a small num if individuals create a new colony, geographically isolated from the original
Gene pool for this new population is small
What is genetic drift?
Due to random nature of alleles being oassed onto offspring, frequency of occurrence of allele will vary
Existence of an allele can disappear from population altogether - more likely in populations with low genetic biodiversity
What do you measure to calculate genetic biodiversity? What is a polymorphic gene?
Polymorphism
Polymorphic gene = Have more than 1 allele. Most genes are monomorphic - single allele for the gene
Why are most genes monomorphic?
To ensure that the basic structure of individuals within a species remains constant
What is the formula for measuring the proportion of genes that are polymorphic?
Proportion of polymorphic gene loci = Number of polymorphic gene loci / total number of loci
Locus (plural - loci) of gene refers to position of genes on chromosome
What does the greater the proportion of polymorphic gene loci mean?
The greater the genetic biodiversity within the population
