Exploring the south american rainforest, a scientist discovers a mysterious organism and brings it back to the lab for further study. what cell characteristics should the scientist examine to tell whether the organism is an animal or plant? why?

In the given case, the scientist should first look for a cell wall as only cells of the plants possess a cell wall. After that he or she should examine for chloroplasts as animal cells do not possess chloroplasts. And finally, he or she should look for the vacuole, that is, if the vacuole is of small size, then it is most probably be an animal cell, however, if it is large then it is most probably a plant cell.  

they deliver oxygen to the blood

that would be called plucking : )

explanation:

''plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the erosion and transportation of individual pieces of bedrock, especially large "joint blocks". as a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock."