SAMOHI — The next champions of an international biology competition could be a couple of local teenagers.

Zack Gold and Christina Tsai, both Santa Monica High School juniors, are among just 20 students out of some 10,000 participants to have made it through two rounds of testing to become USA Biology Olympiad finalists.

The Olympiad is expected to release its official list of finalists today.

The pair from Samohi is headed for the final round this June — an intensive training program set to take place at Purdue University. They’ll attend lectures and participate in labs before taking a two-day test. The top four scorers will go on to represent the U.S. in the International Biology Olympiad competition, which this year is being held in South Korea. Some 60 countries from around the world are expected field teams.

To get this far, Gold and Tsai had to survive two grueling rounds of testing, answering hundreds of biology questions, many of them on topics not covered in your typical course textbook — like the process by which rattlesnake venom kills cells.

“It definitely requires a greater depth of knowledge than AP bio,” said Tsai.

Gold added: “I’d have to say it’s insane. It’s definitely the hardest test I’ve ever taken.”

Both students took AP bio as sophomores and both have experience in academic competitions, though never at such an elite level. Gold participates in the Marine Science Bowl, and Tsai has been on the Science Bowl team.

Gold and Tsai were picked to take the competition exams by Samohi AP Biology teacher and Academic Decathlon coach Ingo Gaida.

In the next few weeks they will be preparing to square off against some of the top biology students in the nation.

“I’m really excited, but I’m also definitely really nervous,” Tsai said. “Everyone else is probably also extremely, extremely talented.”

nickt@smdp.com