1 In the cytoplasm, the mitotic spindle, consisting of microtubules and other proteins, forms between the two pairs of centrioles as they migrate to opposite poles of the cell. 2  The nuclear envelope disappears at the end of prophase. 3  This signals the beginning of the substage called prometaphase.
  Percussion Family. The Timpani is struck by mallets ... any instrument that requires a percussive touch is a member of this family ...surprisingly enough, and a little â¦ known fact, the Piano is also a member of the Percussion Family ... a key must be struck to produce a tone!!5 people found this useful.he Timpani is struck by mallets ... any instrument that requires a percussive touch is a member of this family ...
A soft or hard padded mallet is used to play them; a pedal mechanism is attached to each timpani which changes the tension of the head, thus adjusting the pitch. SOUND PROPERTIES: The timpani sound is created by striking the membrane, or head, with mallets causing the head to vibrate. The tension of the head determines the exact pitch. A looser tension creates a lower pitch and a tighter tension creates a higher pitch.