"We believe our proposals do meet the BBC's core public service criteria of distinctiveness and quality", Dyke said in a statement issued in response to Jowell's ruling.
Jowell said that she believes that a distinctive channel, aimed at a young audience, could be an important part of the BBC's total service.
She has asked the broadcaster to reconsider its original proposal and submit fresh plans for the channel, which would replace its existing channel targeted at the 16-34-year-old market, BBC Choice.
The broadcaster said it welcomed Jowell's decision to approve eight of the nine services it put forward. They include five digital radio stations, including a station dedicated to black culture and music, and an Asian network; an arts and culture TV channel and two children's channels.