This diagram appears to be extremely self contradictiory. In the chart it says that a chromosome is absent of a centromere which implies ecept all of the figures show the presence of a centromere including the one labeled “chromosome with one chromatid.” The “chromosome with one chromatid” label points to a structure with two stands attached by a centromere, the “one” implying that the stand itself is a chromatid except your own definition says that a chromatid has TWO strands connected by a centromere which would mean the whole structure is one chromatid even though your label says it is a chromosome with one chromatid.

The next fugures again refer to the entire strand as a chromosome but your defintion says it can’t be because the centromere should be absent. What is going on here?