Misconception: White strawberries were altered in a lab.

Actually: They were created through old-fashioned crossbreeding.

“Every week or so, I see a tweet about G.M.O. strawberries,” said Karl Haro von Mogel, a co-founder of Biology Fortified, a nonprofit website that publishes articles about genetic engineering. About 40 percent of respondents in a 2013 New York Times/CBS poll of American adults said they thought “most” or “a lot” of fresh fruits and vegetables were genetically engineered.

But, except for a few fruits and vegetables, American produce uses older breeding methods that do not fall under regulations governing genetically engineered crops, and they would not need to be labeled.

Japanese geneticists made seedless watermelons in the 1930s by exposing watermelon seeds to chemicals that doubled their usual pair of chromosomes, and by crossing those with pollen from a regular watermelon. It was because their offspring had an odd number of chromosomes that they could not make seeds of their own; it was not the result of foreign DNA.

And the popular red grapefruit now grown in Texas is the descendant of one of thousands of mutants produced by a breeder in the mid-1960s by bombarding pink grapefruit tree buds with radiation, a technique for accelerating evolution that has yielded new varieties in dozens of crops, including barley and rice. The crops created through that method, called mutagenesis or radiation breeding, can be certified as organic.

If genetic mutation sounds scary, it’s worth remembering that genetic mutations constantly happen in nature, without human intervention. Orange carrots, for instance, arose from a natural mutation and became prevalent only because humans planted them. The purple and yellow ones you might have thought were G.M.O.s were the originals. As for those white pineberries, breeders crossed two species of strawberry to create a hybrid with some of the characteristics of both — combining the genetic diversity that exists in both species.