CELL CYCLE

• Cells A and D show an early and late stage of the same phase of mitosis. What phase is it?

  Prophase

  
• Which cell is in metaphase?

  Cell C

  
• Which cell is in the first phase of mitosis?

  Cell D - early prophase

  
• In Cell A, what structure is labeled X?

  Centriole

  
• Place the diagram in order

  D, A, F, C, E, B

  
• Are cells depicted animal or plant cell?

  Animal cell - due to the presence of cleavage furrow

  
• Interphase - longest phase of the entire cell cycle
• Cell cycle - series of events cells go through as they grow and divide
• Cell grows, prepares for division, then divides to form 2 daughter cells - each of which then begins the cycle again
• CELL CYCLE

  A) cytokinesis

  B) cell division

  C) nuclear division

  D) mitosis

  E) telophase

  F) anaphase

  G) metaphase

  H) prophase

  I) interphase

  
• Interphase —period of cell growth and development
• DNA replication (copying) occurs during Interphase
• During Interphase the cell also grows, carries out normal cell activities, replicates all other organelles
• The cell spends most of its life cycle in Interphase
• Mitosis – division of the nucleus into 2 nuclei, each with the same number of chromosomes
• Mitosis occurs in all the somatic (body) cells
• Why does mitosis occur? 

  So each new daughter cell has nucleus with a complete set of chromosomes
• CELL

  A) aster

  B) nuclear membrane

  
• 4 phases of nuclear division (mitosis), directed by the cell’s DNA (PMAT)

  A) prophase

  B) metaphase

  C) anaphase

  D) telophase

  
• Prophase - Chromosomes coil up
• Prophase - Nuclear envelope disappears
• Prophase - Spindle fibers form
• Metaphase - Chromosomes line up in middle of cell
• Metaphase - Spindle fibers connect to chromosomes
• Anaphase - Chromosome copies divide
• Anaphase - Spindle fibers pull chromosomes to opposite poles
• Telophase - Chromosomes uncoil
• Telophase - Nuclear envelopes form
• Telophase - 2 new nuclei are formed
• Telophase - Spindle fibers disappear
• Cytokinesis — the division of the rest of the cell (cytoplasm and organelles) after the nucleus divides
• In animal cells the cytoplasm pinches in
• In plant cells a cell plate forms
• After mitosis and cytokinesis, the cell returns to Interphase to continue to grow and perform regular cell activities
• ANIMAL AND PLANT CELLS

  A) cleavage furrow

  B) vesicles forming cell plate

  C) wall of parent cell

  D) cell plate

  E) contractile ring of microfilaments

  F) new cell wall

  G) daughter cells

  H) cleavage

  I) cell plate

  J) SEM

  K) TEM

  L) daughter cells

  
• SEM - Scanning electron microscope
• TEM - Transmission electron microscope
• When cells become old or damaged, they die and are replaced with new cells
• CELL CYCLE SUMMARY

  Interphase - Mitosis (PMAT) - Cytokinesis
• INTERPHASE

  • CHROMOSOME APPEARANCE: DNA copies itself in chromatin
  • IMPORTANT EVENTS: DNA replication, cell grows and replicates organelles