sci

• Cell replication/division


  • Cell has to double its contents such as water, organelles, and DNA
• Chromosome


  Refers to a more compressed and coiled status of DNA seen during cell division
• Chromosome


  Condensed version of the chromatin
• Chromosomes consist of the genetic material of organisms
• Somatic cells


  Diploid cells (with two sets of chromosomes)
• Somatic cells


  Function for growth and various metabolic activities besides reproduction
• Sex cells (gametes)


  Haploid cells, the sperm cells and egg cells, that unite during fertilization
• Cell cycle


  Processes happening within the cell as it prepares and executes cell division
• Cell cycle


  1. Interphase

  2. M phase

  3. Cytokinesis
• Interphase


  Longest phase which makes up 90 percent of the cell cycle
• Interphase


  Cell is active metabolically and prepares for the process of division
• Interphase


  1. G1 phase

  2. S phase

  3. G2 phase

  4. G0 phase
• G1 phase


  Cell starts to grow, water content, enzymes, and organelles are doubled, majority of growth occurs
• S phase


  Synthesis phase allows an exact copy of the DNA to be synthesized
• G2 phase


  Continuous growth and preparation division, proteins important for chromosome and mitotic spindle formation are produced
• G0 phase


  Cell is in a resting state (from division), neither preparing to divide or is currently actively dividing
• Checkpoints


  1. G1 checkpoint

  2. G2 checkpoint

  3. Metaphase checkpoint
• G1 checkpoint


  Checks for proper cell size, adequate nutrients, DNA damage, cell growth factors
• G2 checkpoint


  Checks for proper cell size, DNA damage from S phase, initiates apoptosis in cases of irreplaceable errors
• Metaphase checkpoint


  Checks for proper and equal separation of sister chromatids, proper attachment of spindles
• Mitotic phase


  1. Prophase

  2. Prometaphase

  3. Metaphase

  4. Anaphase

  5. Telophase
• Mitotic phase


  Division of the cellular content, immediately followed by or simultaneously occurs with cytokinesis
• Prophase


  • Nuclear disintegration, mitotic spindle extends from the centrosome, chromatin condenses to become visible chromosomes
• Prometaphase


  • Disappearance of the nuclear membrane, microtubules extend from centrosomes, more condensed chromosomes
• Metaphase


  • Centrosome completely located on the opposite poles, chromosomes centrally aligned at metaphase plate
• Anaphase


  • Separation of the sister chromatids, single chromosomes move towards the opposite poles
• Telophase


  • Microtubules detach from the kinetochore, chromosomes start to uncoil
• Cytokinesis in animal cells


  Cleavage furrow starts as a groove along the cell membrane's surface and then pinches up to the cell's center
• Cytokinesis in plant cells

  Cell plate formation starts in the middle of the cell plate and elongates outwardly