That's impossible, the mechanic doesn't exist in this game.
you digivolve a digimon
No, you cannot. I think that Digimon have to be at the same level (Champion, Ultimate, etc) to DNA Digivolve. However, if you have a DNA Digivolved digimon, get one of the digimon you digivolved it with (Like for Silphymon, Aquilamon or Gatomon) and if you DNA Digivolve, it should result in their rookie forms.
level it up
DNA evolution aka 'Jogress evolution' came from Digimon Adventure 02.
DotAgumon doesn't evolve.
garudamon+blossomon or yatagaramon+ karentenmon
In Digimon World Dawn.... you need maximum friendship and level 40
You DNA Digivolve Kongoumon with Yatagaramon.
You can either get them at task canyon or digivolve a birdramon
you can digivolve tokomon to falcomon in digimon ds if yokomon has 60% and up friendship and is lvl 10 above.Info got from: http://www.neoseeker.com/resourcelink.html?rlid=135281&rid=126145
Depending on their stats certain Digimon can DNA digivolve to become new ones. There used to be a list somewhere but I don't know where it went... EDIT: I use the list from http://forums.supercheats.com/topic.php?topic=74877 which gives a full list of DNA Digivolutions AND an Armor Digivolution list.
it can dna digivolve with rosemon to create Rosemon Burst mode