The base of an adenine molecule is made of ribose sugar molecules
From what I can see in the picture, the cell appears that it would take up half of the microscopes view if it were to be pushed to the very edge on one side.
That would be the radius. The radius is half of the diameter, and half of 0.8 mm would be 0.4 mm. The length of the cell is about 0.4 mm.
Now for the width. Since the diameter of the FoV (field of view) is 0.8, we can see that the cell doesn't reach both sides of the circle it is in. It also doesn't appear to take up half of it. So, to get the aprox. width of the cell, we're going to half the radius.
Half of 0.4 mm is 0.2 mm, so the width of your cell is about 0.2 mm.
We must first define these three prominent definitions of species. Biological species concept means that organisms resemble each other because of genes being passed from parent to offspring. Phylogenetic species concept means that organisms resemble each other because they evolved from a common ancestor. Lastly, morphological species concept characterizes species on the structure of their body parts rather than genetic or phylogeny.
In this case, (1) biological species concept is not applicable for extinct species, (2) phylogenetic species concept is based on evolutionary history, (3) morphological species concept relies on similarities in structure, (4) Morphological and phylogenetic species concept accommodates asexual reproduction, and lastly (5) all species concepts are used by scientists in classification.