Dna/animals

• Animals compete for


  • Food
  • Water
  • Shelter
  • Mates
• Plants compete for


  • Light
  • Water
  • Nutrients from soil
  • Space
• Evolution


  The process where living things gradually change over time
• Extinction


  No members of a species exist anymore
• Camel adaptations


  • Big hump to store fat
  • Big feet to walk on sand
  • Coloration for camouflage
  • Big eyelashes to keep out sand
• Polar bear adaptations


  • Large paws to avoid sinking in snow
  • White coloration for camouflage
  • Thick layers of fat for insulation
  • Very thick fur
• Extremophile


  An organism that lives in an extreme environment
• Extremophiles


  • Deep sea fish
  • Bacteria in very salty or hot conditions
• Reasons a species may go extinct

  • Better adapted competition
  • Disease
  • Human predation
  • Climate change
  • Loss of habitat
  • Invasive species
• Natural selection


  Individuals most suited to an environment are more likely to breed, passing on their best characteristics
• Speciation


  One species splitting into two separate species that cannot interbreed
• Types of variation


  • Inherited
  • Environmental
• Purely inherited characteristics


  • Eye color
  • Hair color
  • Blood group
  • Inherited diseases
• Continuous variation


  A characteristic that can have any value within a range
• Discontinuous variation


  A characteristic that can only be certain values
• Fossil


  The remains of a plant or animal that has turned to stone
• Interdependence


  The way living organisms depend on each other to survive, grow and reproduce
• Variation


  Differences in characteristics within a species
• Speciation is the process where one species splits into two separate species that cannot interbreed
• Inherited variation refers to characteristics passed down from parents, not just from mother and father
• This is the year eight adaption and inheritance reverse the classroom
• Extinction


  No members at all survive from a species, often due to geological events, disease, climate change, habitat loss, or hunting by humans
• Evolution


  The process by which living things can gradually change over time
• Adaptations for hot environments

  • Large body and thin legs, wide feet, small concentrated urine, no sweat, large ears, thin hair and eyelashes, hump full of fat, hard mouth
  • Shallow but widespread root systems, spines for protection, no flowers, thick wax covering, thick stem, tall
• Adaptations for cold environments

  • Thick white fur, hollow fur, large feet, small ears, large body and short legs, greasy fur, layer of blubber
  • Very small growing, dark colored leaves covered in wax and hairs, very deep roots, antifreeze sap
• Extremophiles


  Living organisms that live in extreme environments
• Evolution by natural selection

  Individuals within a species show variation in characteristics, and the ones most suited to the environment are more likely to survive and reproduce, passing on their genes
• Lamarck's theory of evolution

  If an organism has to stretch or adapt to its environment, it can pass on those acquired characteristics to its offspring
• Speciation


  A species becomes isolated and diverges into two or more distinct species that can no longer interbreed
• Evolution of peppered moths

  • Light-colored moths survive better in unpolluted environments, dark-colored moths survive better in polluted environments
• Variation


  Can be inherited (from parents) or environmental (from living conditions)
• Truly inherited characteristics


  • Natural eye color
  • Natural hair color
  • Blood group
  • Inherited diseases
• DNA


  The building blocks of life, found in the nucleus of cells, made up of two strands forming a double helix