The variables that stay the same to keep the experiment fair. Ex same amount of sunlight

Plz fast biotechnology is a growing field of applied biology. many crops such as corn have been engineered to be resistant to herbicides. therefore farmers can spray these chemicals to kill weeds growing near the crop without worries of killing the crop itself how does this type of biotechnology work? a. by changing the genetic make up of the crops. b. by causing the crops to kill the weeds. c. by changing the type of crops used. d. by changing the location of the crops.

At which point is crust neither created nor destroyed? island chain mid-ocean ridge divergent boundary transform boundary

What is the starting point in replication called