Mitosis is used to create daughter cells that are genetically identical to its parent cell. This is asexual reproduction. For some organisms, it is how their kind survives. Meiosis is only used in organisms that reproduce sexually. It is used to create 4 daughter cells that are not genetically identical, in order to have independant assortment.
| Your Immune System | |
| Lines of Defense | How it Works |
| The First line of defense is your skin. | When a pathogen interacts with the skin,the skin may recongnize it as an invador. It then alerts the body, the body produces infection fighting chemicals and takes care of it. |
| The second line of defense is the nonspecific response. | This line of defense contains neutrophils and macrophages. Neutrophils stick to the invador, swallows it and kills it with chemicals. Macrophages attack the invador and just engulf it. |
| The Third line of defense is the Specific Response. | This line is made up of helper T cells, B cells and Killer T cell. B cells produce antibodies in response to an intruder. These antibodies are specifically designed to tag an antigen. The Helper T cell then comes along to the taged antigen and destroys it. Killer T cells kill cells in the body that have been infected by a virus or bacteria to keep it from spreading. |
For more information on the Immune System, go to Immune System