I need help with this, please help

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.

Which of these is not a nucleotide base found in dna?

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?