SOMEONE CAME INTO MY HOUSE AND STABBED ME!! IT HURTS SO MUCH HELP!!
Hi, I’m Doctor Renolds! What happened here?
OH MY GOD! LET ME EXAMIN YOUR WOUND!
OH THANK GOD! It’s superficial. let me explain what is about to happen.
What is external regulation?
Our bodies are phenomenal, they quickly act to heal our wounds. Since your wound is superficial, external regulation will take place.
External regulators are proteins that respond to activity outside the cell. Some important external regulators are called growth factors. When you suffer an injury, growth-factor proteins govern the cell cycle.They also play a part in the development of an embroy.
Since the cell has grown large enough, it is going to start dividing soon. A process called mitosis will then take place, but it can’t t happen unless I replicate myself. So, I need to do it now!
There we go! Now mitosis can take place because the internal regulators will signal the mitosis to start
Cyclins and internal regulators did such a good job at regulating the time of cell division!