adaptation

• Things animals compete for

  • Food
  • Water
  • Space (to hunt and for shelter)
  • Mates (to reproduce)
• Things plants compete for

  • Light
  • Water
  • Space
  • Minerals
• Adaptations


  Features that enable an organism to be successful and survive
• Interdependence occurs


  When a predator feeds on just one type of prey
• A cyclic pattern occurs


  Between the populations of the predator and prey
• Species


  Organisms that can mate and produce free offspring
• Genetic material


  Stored in the nucleus in a material called DNA
• DNA


  Long strands called chromosomes
• Section of DNA


  Gene, has information to produce a characteristic
• Evolution


  The slow development of many species over time
• Fossils provide evidence that evolution has occurred
• Natural selection


  The process by which evolution occurs
• There is variation in a population, the most fit survive and reproduce, the offspring inherit the beneficial characteristics
• Gene banks


  Store genetic information of plants and animals for research and for reproduction
• Describe the adaptations plants and animals have to survive different environments and changing seasons
• Plants adapted to life in the desert

  • Waxy layer
  • Stems that can store water
  • Widespread roots
  • Spines instead of leaves
• Animals coping with cold winters

  • Hibernation
  • Migration
  • Growing thicker fur
• Inherited variation


  Result of getting characteristics from parents
• Environmental variation


  Caused by the surroundings
• Continuous variation


  Characteristic that takes any value within a range, plotted on a histogram
• Discontinuous variation


  Characteristic that only results in certain values, plotted on a bar graph
• A species can become extinct if there are no living members left, due to environmental changes, habitat destruction, disease outbreak, or introduction of a new predator or competitor
• DNA


  Found in the nucleus of cells, organized into chromosomes, passed from one generation to the next, contains genetic information
• DNA molecule


  Two strands twisted around each other in a double helix, held together by base pairs
• Components of DNA


  • Strands
  • Base pairs
  • Bonds
• Humans have around 20,000 genes, one copy of chromosomes is called a genome
• Evolution is the change in the inherited characteristics of a population over time through natural selection, which may result in the formation of a new species
• The theory of evolution by natural selection states that all species of living things have evolved from simple life forms that first developed more than three billion years ago
• Natural selection


  The process by which variants that give rise to phenotypes best suited to their environment are selected
• Reasons for extinction


  • Introduction of a new disease
  • Introduction of a new competitor
  • Introduction of a new predator/overhunting
  • Lack of food/prey
  • Environmental change
  • Natural disaster