Yes, Introduction and Conclusions are core parts that need to be included in a ToC. Note that it is not necessary that the chapters have these titles although in the vast majority of cases they do.
The Introduction sets the perspective for the chapter and the Conclusions summarizes the important conclusions reached in the discussion. Hopefully the Conclusions tie in with the perspective(s) set in the Introduction since they constitute the head and tail of the chapter and the partial conclusions reached therein.
In cap off, if you have a heading within the main part of the thesis it should be in the ToC and this includes Introduction and Conclusions. In the case of a chapter, it may be worth providing a more meaty, descriptive title for the introduction that ties in with the theme of the chapter. This is in my opinion less so concerning conclusions.