B4 EVOLUTION

• Describe the stages of natural selection

  There is variation in the population caused by gene mutations, organisms which are best adapted to their environment survive and reproduce, the characteristics/alleles are passed onto the offspring, process repeats over many generations
• How can stone tools and fossils be dated? (3 ways)

  Comparison with other pieces of evidence that have already been dated, from the layer of rock it was found in, radiometric dating
• What are the five kingdoms in the classification method?

  Animals, plants, fungi, protists, prokaryotes
• How can the layer of the rock be used to date a fossil or stone tool?

  The deeper down the layer of rock is, the older the fossil/tool.
• Which fossil was from 4.4 million years ago?

  Ardi

  Which fossil was from 3.2 million years ago?

  Lucy

  Who discovered fossils from 1.6 million years ago?

  Leakey
• What are protists?

  Eukaryotic single-celled organisms
• What are prokaryotes?

  All single celled organisms without a nucleus (e.g. bacteria)
• What are the three domains in the classification method?

  Archaea, Bacteria, Eukaryoata
• What are Archaea?

  Primitive bacteria usually living in extreme environments 
• What are included in Eukaryota?

  Protists, fungi, plants and animals
• What are the stages of selective breeding?

  Cross/breed organisms with desired characteristics, select offspring with the desired characteristic and cross/breed them, repeat over many generations
• What led to the three domain system of classification?

  Genetic analysis and DNA sequencing
• Give disadvantages of selective breeding

  Less variation, losing traits which may be desirable in the future, losing useful genes from the gene pool
• Which process involves modifying the genome of an organism to introduce desirable characteristics?

  Genetic engineering
• What are restriction enzymes used for?

  Cutting the plasmid and cutting the gene from the genome in genetic engineering
• What is ligase used for?

  Inserting the desired gene into the plasmid in genetic engineering
• Why is the same restriction enzyme used to cut the plasmid and the gene?

  So that the sticky ends are complementary
• how to selectively breed

  two individuals of opposite sex with the desired characteristic are selected

  individuals are bred together to produce offspring

  offspring with the desired characteristics are selected and bred

  process repeated over many generations
• autrophic -> can make their own food
• heterotrophs eat other food
• scientists validate the discovery of a new species by publishing finding in journals and attending scientific conferences
• Suggest why the dinosaur fossil record is incomplete: Some have been damaged,soft body tissue decays and some parts may have been moved/eaten