Meiosis #70

• What process forms gametes in sexual reproduction?

  Meiosis
• What are gametes also known as?

  Sex cells
• How much genetic material do gametes contain?

  Half the genetic material
• What do we call cells that contain half the genetic material?

  Haploid cells
• What happens when two gametes combine?

  They form a normal diploid cell
• What type of cells do gametes form when they combine?

  Diploid cells
• What is the first step in meiosis?

  Replicate all of the cell's DNA
• What shape do chromosomes take after DNA replication in meiosis?

  X shape
• How many types of chromosomes do humans have?

  23 different types
• What are maternal chromosomes?

  Chromosomes from the mother
• What are paternal chromosomes?

  Chromosomes from the father
• How many individual chromosomes does each human cell have?

  46 individual chromosomes
• What happens to chromosome pairs during meiosis?

  They are randomly distributed
• What is the result of the first division in meiosis?

  Two cells with different DNA
• What happens during the second division of meiosis?

  Chromosomes are pulled apart again
• How many cells are produced at the end of meiosis?

  Four cells
• Why are gametes genetically unique?

  Due to tiny changes during meiosis
• What do male gametes develop into?

  Sperm cells
• What do female gametes develop into?

  Egg cells
• What happens during fertilization?

  Sperm and egg fuse to form a diploid cell
• What does the diploid cell do after fertilization?

  Divides by mitosis to form an embryo
• What is the final outcome of the fertilized diploid cell?

  A fully grown organism
• What are the main steps of meiosis?

  1. DNA replication
  2. First division: chromosome pairs separate
  3. Second division: sister chromatids separate
  4. Result: four genetically unique gametes
• How does meiosis contribute to genetic diversity?

  • Random distribution of chromosomes
  • Genetic recombination during crossing over
  • Unique combinations of maternal and paternal chromosomes