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 ...
1. timpani-a large hemispherical brass or copper percussion instrument with a drumhead that can be tuned by adjusting the tension on it. kettledrum, tympani, tympanum, kettle. percussion instrument, percussive instrument-a musical instrument in which the sound is produced by one object striking another.impani. pl n. 1. (Instruments) (sometimes functioning as singular) a set of kettledrums, two or more in number.