Classification And Phylogenetics Flashcards
Define classification
The process of naming and organising organisms into groups based on their characteristics
Name the eight groups in the classification hierarchy, from largest to smallest
Domain -> kingdom -> phylum -> class -> order -> family -> genus -> species
What are the two components to a binomial name
Generic name = the genus of the organism belongs to. Two closely related species will share the same genus
Specific name = the species the organism belongs to
What is the advantage of the binomial naming system?
It is universal; an organisms binomial name is the same everywhere in the world
Name the five kingdoms and three domains
Kingdoms = prokaryote, protoctista, fungi, plantae, animalia
Domains = bacteria, archaea, eukaryota
How are organisms classified into kingdoms?
Based on similarities in observable characteristics
How was the domain system of classification developed?
Analysing molecular differences between organisms to determine their evolutionary relationships (phylogeny)
What is the difference between classification and phylogeny
Classification is simply sorting organisms into groups. Phylogeny investigates the evolutionary relationships between organism
Explain how natural selection results in evolution
Random mutations result in new alleles
Some alleles provide an advantage against selection pressures, making an individual more likely to survive and reproduce
Their offspring receive the new allele, and are said to have evolved a new characteristic
How did Darwin and Wallace contribute to the theory of evolution?
Observed that birds have many different beak shapes. Concluded that birds with beak shapes most suited to the food they eat are more likely to survive and therefore pass this beak shape onto their offspring
Give other evidence for the theory of evolution
Fossils = allows us to compare extinct organisms to todays organisms
Genomic DNA = sequencing of genomes have shown how closely related we are to primates
Molecular = proteins are composed of the same 20 amino acids in all organisms
What causes variation
Genetic = mutations, random fertilisation etc
Environmental = climate, diet, culture, etc
Differentiate between intra specific and inter specific variation
Intraspecific = variation within the same species
Interspecific = variation between different species
Differentiate between continuous and discontinuous variation
Continuous = variation exists as gradual changes over a range e.g. height, root length
Discontinuous = variation exists as distinct categories e.g. blood group, bacteria shape
Why might we calculate a spearman’s rank correlation coefficient
To measure correlation between two variables i.e the extent to which changing one variable affects the other variable
