<span>sperm and egg cells uniting to produce fertilized eggs</span>
When cell division is not regulated it can cause a malignant rumour called cancer , radiation is used in chemotherapy to kill the cancer, tumoutsd can also be benign
In order to conduct a research you should have an dependent variable, independent variable and the control variable. so in order to study phototropism, then you should need sun light and the growth of the plant and you must have a control that why you need a dark room.
