Gas exchange in humans is the delivery of oxygen lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs.
Taxonomy is the classification of something, especially organisms.
So the answer is D. All living organisms
Answer:Morphology and Physiology
Explanation:Morphology studies the form,structure and features of an organism this could include the shape,height,color etc while physiology help study the underlaying factor that gives rise to the ways its functions.
This two are key for a Biology to group an organism for when the morphology is know it is possible to classify such organism.
