Middle school and high school students from across Iowa will display their science projects at the 45th annual Iowa State Science and Technology Fair Friday and Saturday.

About 350 students will be involved in this year’s fair, representing 40 schools across the state, said Andrea Spencer, director of the fair. The event is the largest statewide technology fair in Iowa. It will be held in Hilton Coliseum today from 10:30 a.m. to 5:30 p.m. and Saturday from 9 a.m. to 5:30 p.m.

“This year, genetically modified organisms is a hot topic,” she said. Bacteria studies and the effects of weather on honey bees are also projects on display.

“One student has tried measuring the circumference of the Earth to see how close he can come,” Spencer said.

Iowa State has hosted the fair for the past five or six years, said Howard Shapiro, chairman of the science fair board and ISU vice provost for undergraduate programs. The science fair board is in charge of planning the fair and putting it together.

“Last year was my first year going through it,” he said. “I really enjoyed it and I learned a lot. This thing happens, literally, because of hundreds of volunteers.”

He said ISU students may have been involved in the fair before college and may want to judge or just go for fun. ISU faculty, science teachers and representatives from various organizations also participate in the judging.

“There are really two types of judges,” Shapiro said. A team of judges consisting of college professors, science teachers and other volunteers decide the fair winners. Sponsors from different organizations send representatives to judge science projects that merit a special award or scholarship.

The two days of judging will conclude with an awards program Saturday evening.

“Friday is preliminary judging, and then they will all be rejudged on Saturday,” Spencer said.

Judging is based on creative ability, scientific thought, thoroughness, technical skill, clarity and dramatic value.

“We do give blue, red and white ribbons to all the participants,” Shapiro said, “so everybody gets an award, and they all get judging feedback.”

The top 13 middle school and high school individuals in both biological and physical science categories receive prizes or special awards. The top three high school project winners will be sent to the International Science and Engineering Fair. Judges from the Horticulture Club give plants as prizes to their top choices, she said.

Outstanding high school students may also be awarded scholarships. A $5,000 tuition grant will be sponsored by the Iowa Space Grant Consortium in addition to many other awards offered by the Iowa Energy Center, Iowa State, Army/Navy and Iowa Biotechnology Association.

“It is all done by donations,” Spencer said.