Genetics and evolution -B15

• What did Mendel do ?

  mendel bred heterozygous pea plants together. He observed a 3:1 ratio in the phenotype of every trait the majority contained at least 1 dominant allele and the minority contained 2 recessive alleles. His idea wasn’t initially accepted due to blending theory
• explain Darwin’s theory of natural selection ?

  • genetic mutation occurred
  • new advantageous allele
  • more likely to survive and reproduce due to allele
  • advantageous allele passed on to offspring
  • they Can also survive and reproduce so allele becomes more common throughout population
• Explain lamark’s theory?

  . Organism changes its characteristics during its life span

  . offspring inherit the acquired characteristic
• Explain the process of fossilisation:

  • organisms die and get buried
  • soft parts decay
  • hard parts (shells and skeletons) don’t decay
  • mineralisation occurs
  • or they leave imprints in the rock
• Why is the fossil record incomplete ?

  . we haven’t found all of the fossils

  . the conditions were not always right for mineralisation

  . some fossils have been destroyed by geological activity
• Causes of extinction

  • water availability
  • change in weather patterns
  • natural disasters
  • pollution
  • predation
  • new pathogens
  • lack of prey
  • habitat destruction
• Why did Darwin publish of his book?

  Alfred Wallace showed he had reached the same conclusion so Darwin wanted to publish before him
• Arguments for evolution

  • fossil record shows gradual changes over time
  • similarity’s between fossils
• Arguments against evolution

  • fossil record is incomplete
  • common ancestors not proven
  • similarities between fossils could be coincidental
• Explain how speciation occurs

  • geographical isolation
  • differences in environmental conditions
  • genetic variation - due to mutation
  • survive And reproduce
  • advantageous allele inherited
  • different species once cant interbreed
• Who determined the 5 kingdoms ?

  Carl Linnaeus
• What are the 5 kingdoms ?

  animal

  plant

  fungi

  protist

  prokaryote
• Who discovered the 3 domains ?

  Carl Woese
• What are the 3 domains?

  The three domains are Archaea, eubacteria, and Eukaryota
• what is the order of original classification ?

  Kingdom, Phylum, Class, Order, Family, Genus, Species
• What is binomial classification ?

  genus + species name