CIE A Level Biology复习笔记19.1.1 Recombinant DNA
Recombinant DNA The genetic code is universal, meaning that almost every organism uses the same four nitrogenous bases – A, T, C & G. There are a few exceptions This means that the same codons ...
CIE A Level Biology复习笔记18.3.6 Role of IUCN in Conservation
Role of IUCN & CITES in Conservation International cooperation is essential if conservation is to be successful There are several agreements and authorities that exist within and between countr...
CIE A Level Biology复习笔记18.3.5 Controlling Invasive Species
Controlling Invasive Species A species that has moved into an ecosystem where it was previously unknown is an invasive species An invasive species can occur naturally as a result of a species migra...
CIE A Level Biology复习笔记18.3.4 Assisted Reproduction
Assisted Reproduction Endangered mammals tend to have small and isolated populations Small populations are prone to inbreeding and inbreeding depression Inbreeding depression is the reduction in fi...
CIE A Level Biology复习笔记18.3.3 Methods of Conservation
Methods of Conservation An endangered species is a species that is being threatened with extinction Conservation of endangered species can be approached in several different ways Ideally a species ...
CIE A Level Biology复习笔记18.3.2 Reasons for Maintaining Biodiversity
Reasons for Maintaining Biodiversity Biodiversity is the range and variety of genes, species and habitats within a particular region It is made up of three components: Genetic diversity Species div...
CIE A Level Biology复习笔记18.3.1 Reasons for Extinction
Reasons for Extinction Extinction is when a species comes to an end or dies out Extinction is a natural biological process that happens on planet earth and studies of fossils and ancient DNA have s...
CIE A Level Biology复习笔记18.2.7 Simpson's Index
Simpson's Index Once the abundance of different species in an area has been recorded the results can be used to calculate the species diversity or biodiversity for that area Species diversity looks...
CIE A Level Biology复习笔记18.2.6 Spearman's Rank Correlation
Spearman's Rank Correlation If there is an apparent relationship between two variables but the data does not show a normal distribution, Pearson’s linear correlation coefficient should not be used ...
CIE A Level Biology复习笔记18.2.5 Pearson's Linear Correlation
Pearson's Linear Correlation When recording the abundance and distribution of species in an area different trends may be observed Sometimes correlation between two variables can appear in the data ...
CIE A Level Biology复习笔记18.2.4 Testing for Distribution & Abundance
Testing for Distribution & Abundance The distribution of a species describes how it is spread throughout the ecosystem The abundance of a species is the number of individuals of that species Th...
CIE A Level Biology复习笔记18.2.3 Random Sampling
Random Sampling Measuring the different levels of biodiversity within an ecosystem can be a tasking job Finding out which species live in an ecosystem and the size of the populations requires the i...
