Natural selection and genetic modification

    Cards (51)

    • What does natural selection mean?
      Survival of the fittest
    • Why do individuals in a population show genetic variation?
      Due to differences in their alleles
    • How do new alleles arise?
      Through mutation
    • What happens to alleles responsible for useful characteristics?
      They are more likely passed to the next generation
    • How do beneficial characteristics affect a population over time?
      They become more common in the population
    • What do bacteria sometimes develop in their DNA?
      Random mutations
    • What advantage does antibiotic resistance provide to bacteria?
      Better survival in the presence of antibiotics
    • How does a resistant bacterium fare in a treated host?
      It survives longer than non-resistant bacteria
    • What does the spread of antibiotic resistance illustrate?
      Natural selection in bacteria
    • What is a fossil?
      A trace of an ancient organism
    • How are fossils typically found?
      In rocks
    • What does arranging fossils in chronological order show?
      Gradual changes in organisms over time
    • What is the significance of fossils in evolution?
      They provide evidence of species changes
    • What do fossils suggest about human evolution?
      Humans evolved from a common ancestor with apes
    • What are hominids?
      Human beings and their ancestors
    • What do hominid fossils reveal?
      Characteristics between apes and humans
    • How old is the Ardi fossil?
      4.4 million years
    • What does Ardi's foot structure suggest?
      She climbed trees
    • How does Ardi's brain size compare to a chimpanzee's?
      It is about the same size
    • How old is the Lucy fossil?
      3.2 million years
    • What features does Lucy have?
      Mixture of human and ape features
    • How does Lucy's foot structure differ from Ardi's?
      Lucy has arched feet for walking
    • Who organized the expedition to find hominid fossils in 1964?
      Richard Leakey
    • What was Turkana Boy's age?
      1.6 million years
    • How does Turkana Boy's brain size compare to Lucy's?
      It is much larger than Lucy's
    • How can fossils be arranged to show human evolution?
      • Fossils can be placed on a timeline.
      • Ardipithecus species are more ape-like.
      • Homo species are more human-like.
    • What evidence do stone tools provide for human evolution?
      • Homo habilis made simple pebble tools.
      • Homo erectus created more complex tools.
      • Homo sapiens used flint tools and advanced implements.
    • What is stratigraphy?
      The study of rock layers
    • How can carbon-14 dating be used?
      To date carbon-containing materials
    • What are the five kingdoms in the traditional classification system?
      • Animals
      • Plants
      • Fungi
      • Prokaryotes
      • Protists
    • How has the classification system changed over time?
      It now includes genetic analysis
    • Who proposed the three domain system of classification?
      Carl Woese
    • What are the three domains proposed by Woese?
      Archaea, Bacteria, Eukarya
    • What is a disadvantage of selective breeding?
      It reduces the gene pool
    • What health problems can arise from inbreeding?
      Increased chance of genetic defects
    • What is selective breeding?
      Artificial selection of breeding organisms
    • What are the steps involved in selective breeding?
      1. Select existing stock with desired traits.
      2. Breed selected organisms together.
      3. Choose the best offspring for breeding.
      4. Repeat over several generations.
    • How can genetic engineering be useful in agriculture?
      It can create herbicide-resistant crops
    • What is recombinant DNA?
      Two pieces of DNA joined together
    • What role do restriction enzymes play in genetic engineering?
      They cut DNA at specific sequences