Variation And Evolution

    Cards (202)

    • What is meant by variation in biology?
      Differences in characteristics of individuals
    • What are the three main causes of variation?
      Genetic, environmental, and combined causes
    • What is the first cause of variation?
      Inherited alleles
    • How does the environment cause variation in flowers?
      Color depends on the pH of the soil
    • How do genetics and diet influence human height?
      Genetics determine potential; diet affects growth
    • What causes genetic variation in a population?
      Mutations
    • What are mutations?
      Random changes to DNA
    • What is the effect of most mutations on phenotype?
      Most have no effect at all
    • How can some mutations influence phenotype?
      They can lead to traits like tallness
    • What is a key idea about mutations and phenotypes?
      Very rarely can lead to a new phenotype
    • How can a new phenotype be beneficial?
      If the environment changes
    • What happened to wild rabbits in the UK in the 1950s?
      A mutation made them resistant to a virus
    • What is the significance of the mutation in the rabbit population?
      It led to a new beneficial phenotype
    • Where can you find questions on variation for revision?
      In the revision workbook
    • What are the causes of variation in a population?
      • Genetic causes (inherited alleles)
      • Environmental causes (e.g., soil pH)
      • Combined causes (e.g., height influenced by diet)
    • What is the role of mutations in genetic variation?
      • Random changes to DNA
      • Most mutations have no effect
      • Some mutations can influence phenotype
      • Rarely, mutations can lead to new phenotypes
    • What should you be able to describe by the end of the video?
      What's meant by evolution
    • How does evolution take place according to the video?
      Through natural selection
    • How many different species of animals and plants are estimated to exist on Earth?
      Nearly 9 million
    • What percentage of species that have ever lived on Earth are currently alive?
      One percent
    • How long ago did life first develop on Earth?
      More than 3 billion years ago
    • What were the first life-forms on Earth described as?
      Very simple, such as single cells
    • What is the process called where all species of living things have evolved from simple life forms?
      Evolution by natural selection
    • What advantage do rabbits with thicker fur have in a colder environment?
      They are more likely to survive
    • What happens to the alleles for thicker fur over many generations?
      They become more common in the population
    • How does the introduction of a predator affect the rabbit population?
      Rabbits with better eyesight or hearing survive
    • What is the definition of evolution provided in the video?
      Change in inherited characteristics over time
    • What occurs when two populations of one species become so different?
      They can no longer interbreed
    • Why can't pygmy rabbits breed successfully with normal-sized rabbits?
      They are too different in phenotype
    • What is the process of natural selection?
      • Genetic variation exists within a population
      • Environmental changes favor certain traits
      • Individuals with advantageous traits survive and reproduce
      • Beneficial traits are passed to offspring
      • Over generations, these traits become more common
    • What are the implications of speciation?
      • Two populations can no longer interbreed
      • They evolve into distinct species
      • Genetic divergence occurs over time
    • What is another term for selective breeding?
      Artificial selection
    • What should you be able to describe by the end of the video?
      Selective breeding and its impacts
    • What is one impact of selective breeding on food plants?
      It affects domesticated animals
    • What is a disadvantage of selective breeding?
      It can lead to inbreeding
    • What type of animals are wolves?
      Wild animals
    • How did humans utilize wolves thousands of years ago?
      For protection and companionship
    • What process did humans use to produce dogs from wolves?
      Selective breeding
    • What is the first step in selective breeding for large cows?
      Select a mixed population of cows
    • What do we do after selecting the largest male and female cows?
      Breed them together