Classification And Evolution Flashcards
Define classification.
The process of naming and organising organism into groups based on their characteristics.
Name the eight groups in the classification hierarchy.
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
What are the components to a binomial name?
Genus and species. In Latin.
What is the advantage of the binomial naming system?
Universal; an organism’s binomial name is the same everywhere in the world.
What are the three domains? What are there key characteristics?
Archaea - 70S ribosomes, 10 proteins in its RNA polymerase, no cell wall.
Bacteria - 70S ribosomes, 5 proteins in its RNA polymerase, peptidoglycan cell wall.
Eukarya - 80S ribosomes, contains 12 proteins, cellulose, chitin or no cell wall.
What are the six kingdoms?
Eubacteria, archae-bacteria, protoctista, fungi, plantae, animalia.
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 classifiction 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 survive and reproduce.
- Their offspring receive the new allele, and are said to have evolved a new characteristic.
- So much change can occur that a new species can be said to have evolved.
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 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. More complex organisms nearer the surface.
Comparative anatomy - divergent (animals of different species evolve similar characteristics) and convergent (animals diversify from a common ancestor, evolving a different set of specific and adapted features) evolution. Homologous structures appear different on the surface but have the same internal structure.
Comparative biochemistry - Similarities and differences in the proteins and other molecules that control life processes. Can analyse neutral changes in molecules such as cytochrome C, similar ones show close relation. Ribosomal RNA has a very slow rate of substitution. DNA can be sequenced and the results compared. More similar DNA will have diverged from a common ancestor more recently.
What causes variation?
Genetic - mutations, random fertilisation etc.
Environmental - climate, diet, culture, etc.
Differentiate between intraspecific and interspecific.
Intraspecific - variation within the same species.
Interspecific - variation between different species.
