Component 2.1 - Biodiversity Flashcards
What is biodiversity?
1) the number of species
2) the number of individuals within each species
In a given environment
Give an example of how biodiversity can vary?
More plants grow at high light intensity, so a bright environment can support more herbivores and therefore more carnivores.
Where would you expect to find biodiversity hotspots?
Where there is more energy flowing through an ecosystem, like around the equator you ca produce more species and individuals
What are the three main reasons for increase or decrease of biodiversity?
1) Succession
2) Natural selection
3) Human influence
What is succession?
The change in the species structure and composition of an area over time which leads to an increase in animal biodiversity but decreased plant biodiversity. Animals make the area more suitable for others.
When using simpsons index how do you know which of 2 areas have a higher biodiversity?
The higher the numerical value the higher the biodiversity.
What is polymorphism loci?
A genes position on a chromosome is its locus. If a locus has two or more alleles at frequencies greater than would occur by mutation alone is polymorphism.
How does the number of alleles alter biodiversity?
The larger the number of of alleles of one gene, the greater the biodiversity (assess this by looking at the number of alleles at a locus or the proportion of a population that have an allele)
What does the proportion of alleles suggest about biodiversity?
The wider the spread of alleles of a gene the larger the biodiversity of an area.
For example if there were 50% in one allele and 50% in others it would be a larger biodiversity than if it was 98% in one allele.
What is it called when there’s only one base that differs in DNA?
These single base differences are called SNPs - single nucleotide polymorphisms.
What is it called when regions of 20-40 base sequences vary many times in one strand of DNA?
These are called HVR - hyper variable regions.
How can DNA fingerprinting be used to investigate biodiversity?
Comparing the number and position of the bands in the DNA profiles, the more different SNPs and HVRs a population has, the more differences there are in DNA fingerprints, the greater the biodiversity.
How do you calculate Lincoln’s index?
number in 2nd sample x number in 1st sample / number marked in second sample
What factors are affecting biodiversity?
Genetic, environmental and human
Why is DNA fingerprinting used to assess biodiversity at a molecular level?
Due to the difficulties involved in counting every single allele in a population
