Erythropoietin is a HORMONE produced by the KIDNEYS that simulates (causes) the production of RED BLOOD CELLS. Which three organ systems are interacting when this happens?

During the winter, this species of fox has white fur, but in the summer, it has brown fur. what environmental change may have lead to this fox's fur color? snow cover increase in sun's brightness volcanic eruption global warming

What type of organism is a one-celled organism that functions as a single unit? a. bi-celled b. single-celled c. pre-celled d. multi-celled

If the rna molecule in a human has the nucleotide sequence of guu, this would the amino acid valine would be needed to make the protein. how would this cha process was occurring in a mushroom?