Bio chap 6

• What are the two main stages of the cell cycle in eukaryotic cells?

  Interphase and mitotic division
• What activities occur during interphase?

  Producing enzymes or hormones and preparing for division
• What general processes occur during interphase?

  • DNA is replicated and checked for errors
  • Protein synthesis occurs in the cytoplasm
  • Mitochondria grow and divide
  • Chloroplasts grow and divide
  • Normal metabolic processes occur
• What are the three stages of synthesis during interphase?

  G1, S, and G2
• What happens during the G1 phase of the cell cycle?

  The cell increases in size and organelles replicate
• What occurs during the S phase of the cell cycle?

  DNA is replicated in the nucleus
• What happens during the G2 phase of the cell cycle?

  The cell continues to grow and checks duplicated DNA
• What are the two stages of cell division in the mitotic phase?

  Mitosis and cytokinesis
• What is G0 in the cell cycle?

  The stage when the cell leaves the cycle
• Why do cells leave the cell cycle?

  Due to differentiation or DNA damage
• What is a senescent cell?

  Aging cell that stops dividing
• What needs to be checked before a cell divides?

  Size, error-free DNA, and chromosome position
• Why must cells be checked before division?

  To ensure two identical daughter cells are created
• What are checkpoints in the cell cycle?

  Control mechanisms of the cell cycle
• What is the G1 checkpoint?

  Checks requirements before DNA replication starts
• What is the G2 checkpoint?

  Checks for correct DNA replication before mitosis
• What is the spindle assembly checkpoint?

  Checks chromosome attachment to spindles
• What is checked during the G1 checkpoint?

  Cell size, nutrients, growth factors, and DNA damage
• What is checked during the G2 checkpoint?

  Cell size, DNA replication, and DNA damage
• What is checked during the spindle assembly checkpoint?

  Chromosome attachment to spindle
• Why is mitosis important?

  It produces genetically identical daughter cells
• What is a key function of mitosis?

  Needed for growth, repair, and tissue replacement
• What happens to chromosomes during interphase?

  Each chromosome converts into two chromatids
• What are two chromatids joined by?

  Centromere
• Why is it necessary to keep chromatids together during mitosis?

  To ensure precise maneuvering and equal segregation
• What are the stages of mitosis?

  Prophase, metaphase, anaphase, telophase
• What happens during prophase?

  Chromatin condenses into visible chromosomes
• What occurs to the nucleolus during prophase?

  Nucleolus disappears
• What happens to the nuclear membrane during prophase?

  Nuclear membrane begins to disappear
• What forms during prophase to assist in chromosome movement?

  Protein microtubules form spindle fibres
• What happens to centrioles during prophase in animals?

  Centrioles migrate to opposite poles
• How do spindle fibres attach during prophase?

  They attach to specific areas of centromeres
• What happens during metaphase?

  Chromosomes align at the metaphase plate
• What occurs during anaphase?

  Centromeres divide and chromatids are pulled apart
• What causes the V shape during anaphase?

  Chromatids being dragged through the cytosol
• What happens during telophase?

  Chromatids reach poles and reform nuclear membranes
• What happens to chromosomes during telophase?

  They start to uncoil and nucleolus reforms
• What occurs during cytokinesis in animal cells?

  A cleavage furrow forms around the cell
• How does the cell surface membrane behave during cytokinesis in animal cells?

  It is pulled inwards to fuse around the middle
• What happens during cytokinesis in plant cells?

  Vesicles assemble at the metaphase plate