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 ...
Description. With a name that means, the hitting of one body against another, instruments in the percussion family are played by being struck, shaken, or scraped. In the orchestra, the percussion section provides a variety of rhythms, textures and tone colors.Percussion instruments are classified as tuned or untuned.hen struck with felt-tipped wooden sticks, or mallets, timpani produce a specific pitch that is determined by the drum's size. That pitch is fine-tuned by tightening the drumhead with keys and foot pedals. Most orchestras use three or four timpani of varying sizes.