Explain the consequences for evolution if species did not vary

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.

Acommon kind of mechanical weathering is called

Common symptoms of an iron-defiency anemia include muscle weakness shortness of breath and lightheadedness why does iron deficiency causes these symptoms