Angela Simmons
has gone naked ... and her famous uncle Russell Simmons, is partly responsible.

Rev. Run's 24-year-old daughter unveiled her new, nude portrait for PETA last night, showing her in full-on Eve mode -- holding an apple above the words "Eating Meat Is a Sin: Go Vegetarian."

Simmons says she was inspired by uncle Russell to go vegetarian in the first place and says she loves the new diet. "I'm happy with it. I feel lighter—it's a good feeling," she says.

Simmons is hardly the first to take it off for the organization though -- check out the gallery above to get a better look at Angela's shots, plus stars who've stripped for PETA's "I'd Rather Go Naked ..." campaign.