Joanna Cole, the children’s author who conjured Ms. Frizzle and the shape-shifting yellow coach of the “Magic School Bus” books, a best-selling series that hooked millions of young readers on science by taking them on field trips inside the human body, down to the ocean floor, into space and beyond, died July 12 at a nursing home in Sioux City, Iowa. She was 75.

The cause was idiopathic pulmonary fibrosis, said her daughter, Rachel Cole.

Ms. Cole wrote more than 250 books for children but was best known for the “Magic School Bus” series, which debuted in 1986 and came to include 13 titles and dozens of spinoffs, two television shows and a forthcoming movie. The line of books sold 93 million copies in 13 countries, according to Ms. Cole’s publisher, Scholastic, becoming a mainstay of libraries, classrooms and bedroom book nooks.

Some children who grew up reading such titles as “The Magic School Bus at the Waterworks” (1986), “The Magic School Bus Inside the Earth” (1987) and “The Magic School Bus Inside the Human Body” (1989) are now old enough to read the same books to their children.

The occasional update was required over the years for Ms. Frizzle and her romps: When “The Magic School Bus Lost in the Solar System” first appeared in 1990, Pluto was still considered a planet. (Scientists downgraded its status in 2006 to “dwarf planet,” a point reflected in a subsequent edition.) But with their imaginative adventures and exuberant illustrations by Bruce Degen, the books mainly stood the test of time, satisfying millions of children and their roving curiosities about kidneys, sea urchins, comets and more.

The original concept of a series about a zany field-tripping teacher was credited to Craig Walker, a Scholastic editor seeking to revive the tanking sales of science books for children. Ms. Cole, a former elementary school teacher who was already well established as a writer in the genre, jumped at the idea.

In the sometimes-siloed world of children’s book publishing, authors rarely work in close collaboration with the illustrators of their works. Ms. Cole and Degen proved a dynamic exception. Together they created Ms. Frizzle, the wild-haired, wildly dressed teacher who takes her students on even wilder field trips. Degen called upon memories of his high school math instructor with a frizzy bun, according to Booklist, while Ms. Cole paid homage to her junior high school science teacher.

She “was not very adventurous, and she definitely didn’t have Ms. Frizzle’s kooky sense of style,” Ms. Cole told the publication SuperScience in 2011. “But her way of teaching was to rush headfirst into her subject. She carried us along with her enthusiasm. That’s what Ms. Frizzle does.”

Ms. Frizzle acted as both teacher and driver for her students, piloting the bus as it morphed into a steam shovel for its journey into the core of the earth, a rocket ship for its trip into to the solar system and a submarine for “The Magic School Bus on the Ocean Floor” (1992). When Ms. Frizzle took her class to the municipal water works in the debut installment, the bus evaporated into the air in a demonstration of the water cycle.

“Elementary school science should never be the same again after the ‘Magic School Bus’ series is completed,” Katherine Bouton, a science writer, once wrote in the New York Times. “Just as ‘Sesame Street’ revolutionized the teaching of letters and numbers by making it so entertaining that children had no idea they were actually learning something,” she continued, “so the ‘Magic School Bus’ books make science so much fun that the information is almost incidental.”

The books were funny, punny and chockablock with factoids whose acquired knowledge made children feel on top of the world: “The spinning of the Earth makes night and day.” “Snakes smell the air with their forked tongues.” The correct pronunciation of “quartzite” is KWAWRT-site. Exploding with pictures, speech bubbles and miniature school reports, the pages evoked what the interior of a child’s mind might look like, with thoughts and questions bouncing wildly against one another.

Ms. Cole and Degen took their readers back in time to the era of dinosaurs, into a hurricane, into the electric field and into a beehive. In the last published installment of the series, “The Magic School Bus and the Climate Challenge” (2010), they explored climate change and reimagined the bus as a hybrid. “The Magic School Bus Explores Human Evolution” is forthcoming.

Ms. Cole took pride in making her books entertaining, but she took equal or greater pains to make them accurate. The easygoing manner of her texts belied the exhaustive research behind them. She spent months, if not longer, researching a subject and interviewing experts before putting pen to paper. The challenge, she said, was to distill complex scientific concepts into a form that filled the elementary-school set with wonder, but without oversimplifying the matter at hand.

“The force of gravity keeps a school bus firmly on the ground,” she wrote in an addendum to “The Magic School Bus at the Waterworks,” explaining, for the record, that buses do not evaporate into the air. “It cannot rise into the air and enter a cloud, no matter how much you want to miss school that day.”

Joanna Reid Basilea was born in Newark on Aug. 11, 1944. Her mother was a homemaker, and her father a house painter.

When she was growing up, science was her favorite subject. “I discovered in the fifth grade what I liked to do: write reports and stories, make them interesting and/or funny and draw pictures to go along with the words,” she once recalled, according to the reference guide “Major Authors and Illustrators for Children and Young Adults.” “Except for the pictures, I still do that.”

Ms. Cole received a bachelor’s degree in psychology from the City College of New York in 1967 and worked briefly as an elementary school teacher. Finding herself unsuited to the job, she became a children’s book editor before devoting herself to full-time writing.

Her first picture book, published in 1971 with illustrations by Jean Zallinger, was “Cockroaches.” Ms. Cole would have preferred to write about another species, she joked to the Ottawa Citizen, “but you don’t see a lot of butterflies or ladybugs in New York City.”

She quickly began churning out books on topics including botany, insects, dinosaurs, and diurnal and nocturnal animals, as well as series on animal anatomy and how animals are born.

Other books, such as “The New Baby at Your House” (1985) and “Your New Potty” (1989), coached children through sometimes scary milestones. With volumes such as “Asking About Sex and Growing Up” (1988), she came to the rescue of parents in need of their own hand-holding as they helped their children grow up.

Ms. Cole’s survivors include her husband of 54 years, Philip Cole, and their daughter, Rachel Cole, both of Sioux City; a sister; and two grandchildren.

Ms. Cole and Degen ventured into social studies for a “Magic School Bus” spinoff series, “Ms. Frizzle’s Adventures,” that took readers to a medieval castle, imperial China and ancient Egypt.

The original line of books became an animated PBS TV show in the 1990s with Lily Tomlin voicing Ms. Frizzle. In 2017, Netflix began airing a reboot, “The Magic School Bus Rides Again,” with Kate McKinnon as Ms. Frizzle’s sister Fiona. Plans for a live-action “Magic School Bus” film were recently announced, with Elizabeth Banks slated to play the Friz.

When they began their collaboration more than 30 years ago, Ms. Cole and Degen set out to inspire children to see themselves as future doctors and geologists, the next Galileo or Jacques Cousteau. But when they visited schools, they were in for a surprise.

“In every school there’s a teacher who thinks that they are the true Ms. Frizzle,” Degen told “CBS This Morning” in 1992. “They are the ones who are wacky and nutty and they want to get their kids excited and they want to lead them into places where no class has gone before.”