The source of the oxygen given off by plants during photosynthesis is

Which of the following is a cause of a dna mutation? o a. the linking of amino acid subunits into a long chain o b. the transcription of dna into rna o c. an error in the repair of damaged dna d. the diffusion of molecules across the cell membrane submit

Blood has traveled from the heart to the toes. which describes the next step of the circulation process?

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