biology

• eukaryotes

  have DNA in their nucleus

  most often multi cellular

  have mitochondria and chloroplasts
• prokaryotes

  have no nucleus but plasmids instead

  have a cell wall and a membrane

  have no chloroplast or mitochondria

  eg. bacteria cells
• specialised cells

  nerve cells- transmits electrical impulses- branched to make connections

  muscle cell- allows movement - contains many mitochondria

  sperm cell- fertilises the egg-has a long tail, many mitochondria
• stems cells

  they are undifferntiated cells which differentiate into other cells for specific functions.
• embryonic cells from human embryos can differentiate into any call type to treat more diseases like paralysis and type 1 diabetes.

  they can also be classified unethical because using them destroys a potential life
• adult stem cells are found in bone marrow and blood and they produce red blood cells, white blood cells and platelets.
• plant stem cells are found in meristems and are undifferentiated and can differentiate into any type of plant cell which is cheap and quick
• therapeutic cloning can be used to produce stem cells with the same genes as the patient. therefore wouldnt be rejected