Red blood cells are the most common type of blood cell. they are responsible for carrying oxygen from the lungs to all the various body tissues. these cells are shaped like concave discs, and they do not have mitochondria or nuclei. how does this structure the cell carry out its function? a. the lack of organelles, such as nuclei and mitochondria, creates more space for hemoglobin—the molecule that binds and holds oxygen molecules. b. the shape provides a larger surface area with which the cells can bind and transport oxygen. c. the smooth edges of the cells allow them to flow easily through blood vessels without becoming lodged, even in the small capillaries. d. all of these someone who actually knows the answer