In 2023, Mater Dei High School welcomed Biology Teacher Kelly Petro. Since then, he has become a well-known figure among students and staff because of his friendly personality and appeal to the larger student body through his appearances on Monarch TV in the “Don’t Mix These Chemicals” section. Whether he is standing in the front of his biology classroom or on the sidelines at a lacrosse game, Petro has become one of the most respected and well-loved teachers on campus.

Petro currently serves as the college-prep and Honors Biology teacher, holding a Bachelor of Science in Biology from California State University, Fullerton. He approaches teaching by making challenging material attainable and engaging. His lessons go beyond memorizing terms and diagrams, as he helps students truly understand how the biological world around them works. Many students describe his classroom as welcoming and energetic; a place where questions are appreciated and learning feels meaningful, rather than overwhelming. Freshman Natalie Flores, who is currently enrolled in Honors Biology, appreciates the friendly atmosphere that Petro brings to his classroom, specifically for freshmen or incoming students who first engage in high-school-level biology

“When he’s describing and doing his lectures, he knows everything about the topic [that] he’s teaching,” Flores said. “He encourages questions and likes a curious environment.”

As a classroom leader, Petro has many goals for his students. Flores also elaborates on how he balances high expectations with understanding and support.

“He challenges his students a lot, but if you ask questions, he is really good at explaining them,” Flores said. “A lot of people are able to understand after, which enables that comfortable atmosphere.”

Outside the classroom, Petro takes on a very different but equally demanding role as the JV Boys Lacrosse Coach. Balancing teaching with coaching is not easy, yet he brings the same level of passion and dedication to both on the field and in his lessons. Practices are structured but motivating, and players often note that he emphasizes teamwork, discipline, and personal growth just as much as winning games.

Sophomore and JV lacrosse player Jack Duncan shares many wonderful memories he has with Petro. He speaks of the encouragement Petro gives everyone.

“[Petro] loves our team,” Duncan said. “He builds our chemistry as a JV team. He’s very supportive of the team, too. [He] encourages all of us to play at our own level, and he allows us to do basically anything we put our mind to.”

Being a motivational and supportive coach is highly imperative for all sports, not just lacrosse. Duncan elaborates on times when Petro has helped him improve.

“Every time I’m at practice with him, I get better,” Duncan said. “He always tries to encourage us to play our hardest.”

Junior and JV lacrosse player Aliyas Brito states that Petro is both vehement and genuine about not only coaching, but also teaching.

”[Petro] is very passionate about his coaching,” Brito said. “He’s very patient and works well with anybody. He can teach, coach, do anything.”

Despite being fairly new to the staff at Mater Dei, Petro has become one of the most respected and well-loved teachers on campus. Whether he is standing at the front of his biology classroom or on the sidelines at a lacrosse game, his ability to balance both responsibilities of academics and sports highlights his strong commitment to the school.