MITOSIS

• What is the basis of the continuity of life?

  Reproduction of cells, or cell division
• How do unicellular organisms reproduce?

  By the division of one cell
• What do multicellular organisms depend on cell division for?

  Development, growth, and repair
• What is the cell cycle?

  • Life of a cell from formation to division
  • Includes cell division as an integral part
• What are the three main purposes of cell division?

  Reproduction, growth, and tissue renewal
• What is the result of most cell division?

  Daughter cells with identical genetic information
• What are gametes?

  Nonidentical daughter cells (sperm and egg)
• What is a genome?

  All DNA in a cell
• How do prokaryotic and eukaryotic genomes differ?

  Prokaryotic genomes are single DNA, eukaryotic have multiple
• What are chromosomes?

  DNA molecules packaged into structures
• What type of cells are somatic cells?

  Nonreproductive cells with two sets of chromosomes
• How many sets of chromosomes do gametes have?

  Half as many as somatic cells
• What do eukaryotic chromosomes consist of?

  Chromatin
• What is chromatin?

  Complex of DNA and protein that condenses
• What happens to DNA during cell division?

  DNA is replicated and chromosomes condense
• What are sister chromatids?

  Duplicated chromosomes that separate during division
• What is a centromere?

  Narrow waist of the duplicated chromosome
• What is mitosis?

  Division of the nucleus
• What is cytokinesis?

  Division of the cytoplasm
• What is meiosis?

  Variation of cell division producing gametes
• What did Walther Flemming develop in 1882?

  Dyes to observe chromosomes during mitosis
• What are the phases of interphase?

  1. G1 Phase: Cell growth and preparation
  2. S Phase: DNA copying
  3. G2 Phase: Growth and DNA checking
• What occurs during G1 phase?

  Cell grows and prepares for DNA copying
• What happens during S phase?

  Cell copies its DNA
• What occurs during G2 phase?

  Cell checks DNA for mistakes and prepares for mitosis
• What is the purpose of mitosis?

  To produce body cells
• What does mitosis yield?

  Two diploid identical daughter cells
• What is the mitotic spindle?

  Apparatus controlling chromosome movement during mitosis
• What happens during prophase?

  Assembly of spindle microtubules begins
• What is an aster?

  Radial array of short microtubules
• What occurs during prometaphase?

  Spindle microtubules attach to kinetochores
• What happens during metaphase?

  Chromosomes line up at the metaphase plate
• What occurs during anaphase?

  Sister chromatids separate and move apart
• What happens during telophase?

  Genetically identical daughter nuclei form
• How does cytokinesis occur in animal cells?

  By cleavage furrow formation
• How does cytokinesis occur in plant cells?

  By cell plate formation
• What is asexual reproduction in prokaryotes?

  • Type of cell division
  • How bacteria and archaea reproduce
  • Involves chromosome replication and separation
• What is binary fission?

  Process where prokaryotes replicate and divide
• What is cell regulation?

  Coordination of cell division timing and rates
• How does cell division frequency vary among different cells?

  • Embryo: < 20 minutes cycle
  • Skin cells: 12-24 hours cycle
  • Liver cells: once every year or two
  • Mature nerve and muscle cells: do not divide