meiosis

• What type of cell division is meiosis?

  Meiosis is a type of cell division
• How does meiosis differ from mitosis in terms of genetic variation?

  Meiosis produces genetically different daughter cells
• How many nuclear divisions occur in meiosis?

  Two nuclear divisions occur in meiosis
• What type of daughter cells does meiosis produce?

  Meiosis produces haploid daughter cells
• What does haploid mean in terms of chromosome sets?

  Haploid means one set of chromosomes
• What is the chromosome composition of the parent cell before interphase?

  Two copies of each chromosome type
• What happens to chromosomes during interphase before meiosis?

  Chromosomes double in number
• What are the two mechanisms that introduce variation in meiosis?

  Independent segregation and crossing over
• When do independent segregation and crossing over occur in meiosis?

  During the first division of meiosis
• What does independent segregation refer to in meiosis?

  Homologous chromosomes align randomly at the equator
• What is a homologous pair of chromosomes?

  Two chromosomes with the same genes but different alleles
• How can you calculate the number of possible combinations of chromosomes in gametes?

  Using the formula $2^n$
• How many homologous pairs of chromosomes do humans have?

  Humans have 23 pairs of chromosomes
• What is the total number of possible combinations of chromosomes in human gametes?

  Over 8 million combinations
• What is crossing over in meiosis?

  Homologous chromosomes exchange genetic material
• What happens to chromatids during crossing over?

  They can break and recombine with each other
• What is the result of crossing over in gametes?

  New combinations of alleles in gametes
• What are the key differences between meiosis and mitosis?

  • Meiosis has two nuclear divisions; mitosis has one.
  • Meiosis produces haploid cells; mitosis produces diploid cells.
  • Meiosis introduces genetic variation; mitosis produces identical cells.
• What is the notation for diploid cells?

  Diploid cells are represented as 2n
• What should you look for in a lifecycle diagram to identify meiosis?

  Where diploid cells become haploid cells
• Why is it important to identify diploid and haploid cells in lifecycle diagrams?

  To locate where meiosis occurs in the lifecycle
• What is the significance of fertilization in terms of genetic variation?

  It combines random egg and sperm for variation
• How many possible combinations of chromosomes result from fertilization in humans?

  Approximately $7.04 \times 10^{13}$ combinations
• Why are identical twins genetically identical?

  They originate from the same fertilized egg
• What are the key takeaways about meiosis?

  • Meiosis introduces genetic variation.
  • It involves two nuclear divisions.
  • It produces haploid daughter cells.
  • It includes independent segregation and crossing over.