cell cycle and cancer

• What distinguishes living organisms from nonliving matter?

  The ability to reproduce
• How do unicellular organisms reproduce?

  By division of one cell reproducing the entire organism
• What are the key reasons multicellular organisms depend on cell division?

  • Development from a fertilized cell
  • Growth
  • Repair
• What is the cell cycle?

  The life of a cell from formation to its own division

  
• What is the process by which a cell divides its genetic material?

  Mitosis

  
• What is the process that divides organelles and cytoplasm?

  Cytokinesis

  
• What happens when the cell cycle control system malfunctions?

  It can lead to uncontrolled cell division

  
• What type of daughter cells does mitosis produce?

  Genetically identical daughter cells

  
• What type of division produces gametes?

  Meiosis
• What constitutes a cell's genome?

  • All the DNA in a cell
  • Can consist of a single DNA molecule (prokaryotic)
  • Can consist of multiple DNA molecules (eukaryotic)
• What are chromosomes made of?

  DNA molecules packaged into structures
• How many sets of chromosomes do somatic cells have?

  Two sets
• How many chromosomes do gametes have compared to somatic cells?

  Half as many chromosomes
• What is chromatin?

  • A complex of DNA and protein
  • Condenses during cell division

  
• What happens to DNA before cell division?

  DNA is replicated and chromosomes condense

  
• What are sister chromatids?

  Duplicated chromosomes that are attached at the centromere

  
• What is the centromere?

  The narrow waist of the duplicated chromosome

  
• What occurs during cell division regarding sister chromatids?

  They separate and move into two nuclei

  
• What are the phases of the cell cycle?

  • Mitotic (M) phase: mitosis and cytokinesis
  • Interphase: G1, S, G2 phases

  
• What occurs during the G1 phase of interphase?

  Growth and everyday tasks such as making proteins

  
• What happens during the S phase of interphase?

  DNA is copied so each cell gets a copy

  
• What is the purpose of the G2 phase of interphase?

  To prepare for division and produce proteins, organelles, and membranes

  
• How is mitosis conventionally divided?

  • Prophase
  • Prometaphase
  • Metaphase
  • Anaphase
  • Telophase

  
• What is the mitotic spindle?

  A structure of microtubules that controls chromosome movement during mitosis

  
• What happens to the centrosome during interphase?

  It replicates and forms two centrosomes that migrate to opposite ends of the cell

  
• What occurs during prometaphase?

  Some spindle microtubules attach to kinetochores and move the chromosomes

  
• What is the metaphase plate?

  The midway point between the spindle’s two poles where chromosomes line up

  
• What happens during anaphase?

  Sister chromatids separate and move toward opposite ends of the cell

  
• How do microtubules behave during anaphase?

  They shorten by depolymerizing at their kinetochore ends

  
• What occurs at the end of anaphase?

  Duplicate groups of chromosomes arrive at opposite ends of the elongated parent cell
• What is the process of cytokinesis in animal cells?

  It occurs by cleavage, forming a cleavage furrow

  
• How does cytokinesis occur in plant cells?

  A cell plate forms during cytokinesis

  
• What are the stages of mitosis in plant cells?

  1. Prophase: Chromatin condenses, nucleolus disappears
  2. Prometaphase: Discrete chromosomes visible, nuclear envelope fragments
  3. Metaphase: Chromosomes at the metaphase plate
  4. Anaphase: Chromatids separate and move to cell ends
  5. Telophase: Daughter nuclei form, cytokinesis starts

  
• What is binary fission?

  A type of cell division in prokaryotes

  
• How do prokaryotes reproduce during binary fission?

  The chromosome replicates and the two daughter chromosomes move apart

  
• What regulates the timing and rate of cell division?

  • Molecular signals
  • Cell cycle control system
• What is the cell cycle control system compared to?

  A timing device of a washing machine
• What are checkpoints in the cell cycle control system?

  Specific points where the cell cycle stops until a go-ahead signal is received

  
• Which checkpoint is considered the most important for many cells?

  The G1 checkpoint

  
• What happens if a cell does not receive a go-ahead signal at the G1 checkpoint?

  It exits the cycle and enters a nondividing state called G0 phase