What is true of experimental designs that are used in scientific research

In what for do plants utilize nitrogen? why do they need nitrogen?

How can you approximate the number of calories required to keep you in energy balance?

Plz ! a scientist wants to produce a cow that makes a particular human protein in it’s milk the desired protein causes blood to clot and can be used to treat hemophilia (a blood clotting disorder). which of the following would be best for the scientist to use? a. genetic crosses. b. cloning. c. selective breeding. d. genetic engineering.