Biology: Inheritance, Variation and Evolution
What evidence do we have for evolution?
Fossils and antibiotic resistence in bacteria
Fossils
Antibiotic resistence
Fossils and antibiotic resistence
Why is Darwin's theory for evolution now widely accepted?
Characteristics passed onto offspring through genes, fossil evidence, antibiotic resistence
Evidence of passed on genetics
Fossil evidence
Antibiotic resitence
What are fossils?
Remains of organisms from millions of years ago, found in rocks
How can fossils form?
Parts of animals didn't decay as conditions for adequate decaying were absent. As organisms decayed, they were replaced by minerals. Footprints/ burrows/ rootlet trances
Why is there little evidence of early life forms?
Had soft bodies, meaning they left little traces, any traces left have been destroyed by geographical activity.
What can we learn from fossils?
How much or how little organisms have changed as life developed on Earth.
What is extinction?
No remaining individuals of the species alive
What factors may contribute to the extinction of a species?
new predators/ new competitors/ new diseases/ natural disasters/ loss of habitat
Why do bacteria evolve rapidly?
Reproduce at fast rate
What are antibiotic resistent bacteria?
Bacteria not killed by antibiotics
Why do resistent bacteria spread?
People are not immune and there is no effective treatment
How can we reduce the development of antibiotic resistent strains?
Antibiotics should not be prescribed for viral infections or non bacterial infactions. patients should complete their whole course
Why are we unlikely to keep up with emergence of new resistent strains?
Development of antibiotics is slow and expensive
Who developed the traditional classification system?
Carl Linnaeus
Linnaeus
How did linnaeus classify living things?
Kingdom->Phylum->Class->Order->Family->Genus->Species
How are organisms named?
Genus+species
Genus and species
Why were new models of classification proposed?
Evidence of internal structures are more developed due to improvemements to microscopes and understanding of biochemical processes
Who developed the 3-domain system?
Carl Woese
Woese
How are organisms divided in the 3-domain system?
Archaea, Bacteria, Eukaryotic
What are archaea?
Primitive bacteria usually living in extreme conditions
What are eukaryota?
Protists, fungi, plants and animals
What are evolutionary trees?
A method used by scientists to show hoe they beleive organisms are related