Disney and Netflix officials said Friday they're not sure why references to chromosomes and gender were removed from a 21-year-old episode of "Bill Nye the Science Guy," which is available now for online streaming.

"It sounds like it was a business-as-usual kind of clearance issue from ten years ago," a Disney official familiar with the matter told the Washington Examiner.

The official suggested the edit likely occurred about a decade ago when the company first made the kid's television program available online.

The 1996 episode, "Probability," originally featured a cast member saying, "I'm a girl. Could have just as easily been a boy, though, because the probability of becoming a girl is always 1 in 2."

"See, inside each of our cells are these things called chromosomes, and they control whether we become a boy or a girl, " she added. "See, there are only two possibilities: XX, a girl, or XY, a boy."

That segment has since been removed, and it is not available in the version that is now streaming on Netflix, the Washington Free Beacon was first to report.

A a spokeswoman for the online streaming service stressed Friday that they had nothing to do with the edits.

"Netflix did not edit 'Bill Nye The Science Guy,'" Elektra Gray told the Examiner. "It was delivered to us that way by Buena Vista TV."

Buena Vista TV mostly shuttered in 2007. It is now part of the Walt Disney Company's much broader "Disney–ABC Domestic Television" group.

The Disney official told the Examiner they're still investigating the matter, and said they would likely have more information available next week.

Nye's new program, "Bill Nye Saves the World," which is exclusive to Netflix, departs from his old television show's position on gender.

"Gender is like sex, it's on the spectrum," Nye said in one of his newer episodes.

News that Nye's old television program has been edited for Netflix comes on the heels of the premiere of his new online show, which takes a very progressive approach to a number of issues, including climate change, world population and gender.

For some critics, the new Netflix show has been an unpleasant departure from Nye's old children's program, which focused exclusively on traditional and non-controversial science theories.

"Our genes are stories in parts of our cells called chromosomes," he said episode three of season five of his old program. "Chromosomes contain all of the genetic information; all the instructions you need to make a person. Now humans have 23 pairs of chromosomes for a total of 46. It's like the instructions are stored in 46 books and the books are divided into chapters, and each chapter is like a gene."

He added, "Now humans have about 8,000 genes. It's like we have 80,000 chapters in 46 books. Now if you're a cell in a body, you don't need to read every chapter. If you're a nose cell, you just read the chapter about noses. If you're a hand cell, you just read the chapter about hands. If you're an eye cell, you just read the chapter about eyes. See, in a way, they're all different names for different parts of the same thing: Chromosome, genes, pieces of DNA, books chapters, letters. It's pretty good reading."

In contrast, viewers today are now treated to Nye's theories on gender fluidity and whether there ought to be a cap on the number of children that couples in developed countries should be allowed to have.