variation, inheritance and evolution

• What is the structure of DNA?

  Double helix structure
• What do the multicolored lines in DNA represent?

  Base pairs that make up genetic code
• What is a gene?

  A tiny section of a chromosome
• What is a genome?

  The entire set of genetic material in an organism
• What are the two types of reproduction?

  Sexual and asexual reproduction
• What characterizes sexual reproduction?

  Involves two parents and produces gametes
• How does asexual reproduction differ from sexual reproduction?

  Asexual reproduction produces identical offspring
• What is meiosis?

  A type of cell division that produces gametes
• What are the stages of meiosis?

  1. DNA duplication
  2. Chromosomes line up in the center
  3. Chromosomes are pulled apart
  4. Cells divide into four gametes
• What do gametes contain?

  Half the DNA required for a body cell
• What does a Punnett square illustrate?

  The genetic combinations of offspring
• What chromosomes do males have?

  XY chromosomes
• What chromosomes do females have?

  XX chromosomes
• What is the probability of having a male or female offspring?

  50% chance for each
• What is genetic variation?

  Differences in genes and alleles among organisms
• What can cause genetic variation?

  Mutations and environmental factors
• What are two common genetic disorders?

  Polydactyly and cystic fibrosis
• What is environmental variation?

  Changes caused by factors other than genes
• How can identical twins show environmental variation?

  Different diets and lifestyles affect growth
• What is speciation?

  When a species evolves into a new species
• What is extinction?

  When a species is wiped out completely
• What factors can cause extinction?

  Environmental changes, predators, and competition
• What is Darwin's theory of natural selection?

  Survival of the fittest through natural variation
• How does natural selection affect giraffes?

  Longer necks help reach higher food
• What is an advantageous allele?

  • An allele that provides a survival benefit
  • Increases reproductive success
  • Passed on to future generations
• What are the three domains of life?

  • Archaea
  • Bacteria
  • Eukarya
• What are the seven levels of classification?

  1. Kingdom
  2. Phylum
  3. Class
  4. Order
  5. Family
  6. Genus
  7. Species
• What mnemonic can help remember the classification levels?

  Kevin's poor cow only feels good sometimes
• What is the final topic mentioned in the video?

  Ecology