Unit 4.2 From a single cell to a multicellular organism

• Chromosomes in the nucleus carry genetic information
• New cells are formed by cell division, increasing the number of cells in multicellular organisms
• Process of cell division:

  • Individual chromosomes are not visible before division
  • Genetic materials make copies of themselves
  • Nucleus disintegrates, chromosomes appear as X-shaped
  • Chromosomes move to opposite sides, nuclei form, cytoplasm divides, new cells are formed
• The newly divided cells grow to full size by taking in nutrients and may undergo further cell division
• Under genetic control, some cells undergo cell differentiation to become specialized for specific functions