4.2.2: Classification and evolution Flashcards
Define classification.
The process of naming and organising organisms into groups based on their characteristics.
Name the eight groups an organism can be classified into, 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 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 organism’s 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 a kingdom?
Based on similarities in observable characteristics
How was the domain system of classification developed?
By 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 organisms.
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 today’s 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 intraspecific and interspecific
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.
