Is this right i’m confused?

Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the a) atmosphere. b) biosphere. c) hydrosphere. d) lithosphere.

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.

Describe your dna model. which part do the straws represent? the pushpins? the paper clips and the black dots you made with the marker?