UCD haha
i had really weak backgrounds on ochem, okay about gc and bio
before i started studying i cant even do ochem really well but ironically now, ochem is my highest scoring area on science sections. everything is doable in my opinion
and all the courses i took so far, microbiology, evolution, molecular cellular biology, etc all helped me for biology sections but still biology is my weakest area..
do not worry about background, i think DAT asks really general questions (not too much in-depth)
so you will be good to go as long as you study and have some high school level background of chemistry, biology and math.
Chads video for GC, OC
cliffs Ap biology for bio
Crack DAT PAT for PAT
Destroyer for all science and math
will be must prep materials you should get!
hope this helps!