Should museums rely on Wikipedia
as a source of information?

Para mi, no.    

Por qué la gente que escribe en Wikipedia, esta informada de otra fuente... y no sabe realmente si cierto o no, no llega a ser valido en un 100%, según yo¿¿??

the correct answer for this question is:

it is system invented in 1872 that produced the first illusion of movement. basically it was a disk with a series of drawings around the edge, showing the same object in slightly different poses. when it was spun, it created the illusion of movement.

found this online : )

i'm not sure i completely understand your question, but i will do my best.

i think the answer you are looking for is sequence. (see below)

a repeated melodic fragment would be best defined as repetition, while repeated chords (different or the same) could be a chord progression. however, you then mentioned the chord and melodic fragment beginning on higher or lower pitches, in that case, the answer could be best defined as a sequence. the definition of a sequence is as follows: "the restatement of a motif or longer melodic (or harmonic) passage at a higher or lower pitch in the same voice."

let me know if this !