can a nikon slr 35mm lens be used on a nikon digital camera?

Yes

Absolutely .. that is what is so good about Nikon’s .. even the old manual focus lenses from 1959 can be used with a little $ 15 AI modification … any AI lens forward can be used. I use all my old Nikkor lenses on my D100 and D200 DSLR’s.

Since your N55 is a auto-focus camera, all of its lenses will work on the D70 or D80 DSLR

There are NO disadvantages using 35mm Nikon “film” lenses on a DSLR

You can use ‘em, but remember the picture angle of the image (angle of view, field of view) will be that of a lens with 1.5X the focal length.

And just fyi the “G” means the lens does not have an aperture ring. The mount is actually referred to as “Nikon F”.

Hope this helps.

The good news is that your Nikon 35mm af lenses will fit and function perfectly on a D70 or D80. The better news is that because the Nikon digital sensor is smaller than 35mm, you’ll only be using the “sweet-spot”, or center of each lens when shooting.

As for the 1.5 factor you’ve read about above, what that means is that the 70-200mm lens will give you the effective view of a 105-300mm! Basically, multiply any lens focal length by 1.5 and you’ll see the equivalent on your new digital.

For example, I’ve used an older Nikon AF 75-300mm on my D70 and D200 for an effective 107-400mm lens. Does it work? Here’s some examples from a recent shoot with that exact combination.
http://www.spmsportspage.com/images/college/football/2007/Maryland-14-Oregon-State-21-Emerald-Bowl-12-28/index.html

Nikon has been wonderful with keeping compatibility on their lenses and bodies for much longer than most other camera makers.
http://www.kenrockwell.com/nikon/compatibility.htm
http://www.kenrockwell.com/nikon/compatibility-lens.htm

I hope this is helpful.