Mitosis and the Cell Cycle

• What is the role of the cell cycle?

  Growth and repair of cells
• When does mitosis occur?

  After interphase, during nuclear division and before cytokinesis
• Which domain has cells that divide by mitosis?

  Eukaryotic domain.
• What is the difference between binary fission and mitosis?

  Binary fission is the asexual reproduction of bacteria which have no nucleus whereas mitosis occurs in eukaryotes with a nucleus
• How is mitosis different to meiosis?

  Mitosis- cell division in the zygote

  Meiosis- cell division of gametes
• What is the cell cycle?

  The cell cycle is the series of events that take place in a cell leading to its division and duplication.

  IPMATC- In Paris Mrs Almehaidab Took Cocaine

  Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
• What happens during the Interphase?

  Organelles and DNA must double.

  • G1- newly formed cell prepares for division
  • S- DNA replication involving DNA polymerase and helicase
  • G2- further growth of organelles, increasing in number
• What happens during cytokinesis?

  Cytoplasmic division
• What happens during prophase?

  • Chromosomes condense and become visible.
  • Centrioles move to opposite poles of the cell and spindles form.
  • The nuclear envelope breaks down.
• What happens during Metaphase?

  • sister chromatids move to equator
  • spindles attach to centromeres/ kinetichores
• What happens during anaphase?

  Chromosomes are separated and pulled apart towards poles
• What happens during telophase?

  During telophase, the nuclear membrane reforms around the separated chromosomes, the spindle fibers disappear, and the cell begins to divide into two daughter cells.
• What happens during cytokinesis?

  Cytoplasm is divided to form two daughter cells.

  Organelles are arranged at opposite ends of the cell.
• During Prophase and Metaphase, the duplicated, homologous chromosomes are known as sister chromatids however, after separation in anaphase and telophase, they are known as two chromosomes.
• What does homologous mean?

  The chromosomes are the same height/ length and the gene loci is at the same position
• What does autosomal mean?

  Autosomal refers to the non-sex chromosomes in an organism.

  • inheritance of autosomal chromosomes is the same in both males and females
• What are the sex chromosomes?

  Females- homologous XX chromosomes

  Males- non homologous XY chromosomes

  • inheritance of sex linked disorders is different in males and females
• How is DNA organised on a chromosome?

  DNA is wrapped around histone proteins to form chromatin. The chromatin is further condensed by attaching it to protein scaffolds to form loops which fold to create chromosomes
• What is the size order?

  DNA, histone, chromatin, protein scaffold, chromosome