A gender diversity lesson at a California elementary school that featured single-sex geckos and transgender clownfish has angered conservative critics, who question its appropriateness for in-class instruction.
Students in all grades at Oakland's Redwood Heights Elementary School got an introductory lesson on the topic on Monday. Fox News was allowed to sit in on the lessons, which included teachings to kindergartners and fourth-graders.
The lessons were presented by an outside anti-bullying educational group called Gender Spectrum, paid for with a $1,500 grant from the California Teachers Union.
Joel Baum, director of education and training for Gender Spectrum, taught the classes. In the kindergarten class he asked the 5- and 6-year-olds to identify if a toy was a "girl toy" or a "boy toy" or both. He also asked which students liked the color pink, prompting many to raise their hands, to which he responded that that boys can like pink, too.
In the fourth-grade class, Baum focused on specific animal species, like sea horses, where the males can have or take care of the children. He suggested that even if someone was born with male “private parts” but identified more with being a girl, that was something to be “accepted” and “respected.”
Students in the class were given cards, which included information on all-girl geckos and transgender clownfish, to illustrate the variations in nature that occur in humans, too.
“Gender identity is one’s own sense of themselves. Do they know themselves to be a girl? Do they know themselves to be a boy? Do they know themselves to be a combination?” Baum said. "Gender identity is a spectrum where people can be girls, feel like girls, they feel like boys, they feel like both, or they can feel like neither.”
Oakland Unified School District spokesman Troy Flint told FoxNews.com that the two-day lesson plan for all 350 students at the school was intended to emphasize that not all children will conform to gender norms.
"What it does emphasize is that there are differences," Flint said. "And that not all children will conform to gender norms around areas such as clothing or hair, or the colors they prefer. We should be accepting of these differences in the interest of creating an environment where all children are welcome."
Flint said the two-day lessons were given to students in age-appropriate groups, with kindergartners and first-grade students paired together.
Second- and third-grade students were another group, and another was made up of fourth- and fifth-grade students, he said. The lessons, which were required under school district policy to address issues of gender identity, were not intended to advocate a "particular lifestyle," Flint said.
"But we are trying to promote a level of acceptance that will allow all students to participate in school equally, and that is an important equity issue, which is supported by federal, state and local law, as well as school board policy," he said.
Principal Sara Stone has said the lessons are part of a larger effort to provide a more welcoming and safer classroom environment.
Critics, however, were unmoved by that explanation, claiming the lesson does not represent the values of most Oakland residents.
"This instruction does not represent the values of the majority of families in Oakland," attorney Kevin Snider of the Pacific Justice Institute said in a written statement. "Though to many this may seem extreme, based upon some of the bills now pending in the Capitol, such as SB 48, this will be the new normal in California’s K-12 public schools."
Brad Dacus, president of The Pacific Justice Institute, told Fox News that three families chose to keep their kids home that day.
Legal counsel is now being provided to parents who opposed the lessons, Snider said.
"Unfortunately, many parents in the school are unaware that this is being taught," he said. "If you are a parent of a child enrolled in a school where this instruction is taking place, you may consider keeping your child home on days when this material is being presented."
Flint said all parents were informed of the lesson in advance, adding that just three families kept their children home from school during the lessons.
In a blog posting on the website for Media Research Center, a conservative watchdog group, Erin Brown said the plans were the latest example of a "gender-bending" agenda infiltrating mainstream culture.
"This is only the latest example of what seems to be a New-Age, gender-bending agenda pushed into the mainstream media by those who refuse to accept the traditional sex differences between men and women," Brown wrote.
To further illustrate her point, Brown also cited a Toronto couple who has riled some for refusing to assign a specific gender to their third child and an advertisement released earlier this year by clothing company J. Crew that depicting a 5-year-old boy with pink toenails.
The Associated Press contributed to this report.