Detroit (CNN) -- The judge in the federal trial of alleged "underwear bomber" Umar Farouk AbdulMutallab refused Tuesday to prevent the prosecution from calling the device he allegedly carried a "bomb."
U.S. District Judge Nancy Edmunds also refused to exclude a photo of AbdulMutallab's burned genitals from the evidence.
Before the prosecution began its opening statement, defense standby counsel Anthony Chambers asked that the prosecutors not be allowed to use the words "explosive device" or "bomb" during the trial. It's up to the jury to decide whether the device AbdulMutallab was carrying was a bomb, Chambers argued.
"I'm going to deny that motion," responded Edmunds. "It makes no sense whatsoever."
As for the photo, the judge said it did not seem "unusually prejudicial."
AbdulMutallab, accused of trying to detonate an explosive device in his underwear aboard a Christmas 2009 flight to Detroit, has said he will represent himself.
The prosecution delivered a 90-minute opening statement. The defense said it would reserve the right to give an opening statement at a later point in the trial in the U.S. District Court for the Eastern District of Michigan. At one point, AbdulMutallab joined the attorneys for a sidebar with the judge.
While at previous court appearances AbdulMutallab has had outbursts -- including yelling "Osama's alive," a reference to Osama bin Laden, according to a court official -- he remained calm Tuesday. AbdulMutallab wore a traditional African gown, gray with gold-colored braiding.
AbdulMutallab was indicted on charges including attempted use of a weapon of mass destruction, conspiracy to commit an act of terrorism, and possession of a firearm or destructive device in furtherance of an act of violence.
He has pleaded not guilty to the charges.
He was a passenger on Northwest Airlines Flight 253 en route from the Netherlands to Detroit on Christmas Day 2009.
U.S. officials say the terror group al Qaeda in the Arabian Peninsula was behind the alleged bombing attempt.
Jonathan Tukel, chief of the National Security Unit for the U.S. Attorney's Office in the Eastern District of Michigan, laid out details of the flight in his opening statement.
Passengers were from 26 different countries, most of them American and Dutch, he said. "Everyone had someplace to be. All but one." Pointing to AbdulMutallab, Tukel said, "His sole reason for being on Flight 253 was to kill all of the passengers and himself. He thought he'd end up in heaven."
After taking numerous trips to the bathroom, AbdulMutallab went back to the bathroom about an hour before the plane was to land, "to purify himself to die," Tukel said. AbdulMutallab did not eat or drink on the plane, a fast that was part of ritual purification, Tukel said.
A witness testified that AbdulMutallab was in the bathroom for about 15 to 20 minutes, which seemed long to the passenger, Tukel said.
When AbdulMutallab returned to his seat, he pulled a blanket over his head, "pushed the plunger on the bomb and prepared to die," Tukel said.
Passengers heard a loud noise, which sounded like a firecracker, Tukel said. AbdulMutallab became enveloped in a fireball which then spread to the wall and carpeting of the plane, yet he remained in his seat "expressionless, completely blank," Tukel said.
Four passengers helped subdue him and tried to put out the fire, Tukel said, and AbdulMutallab was escorted up to first class.
When a flight attendant asked him what he had in his pockets, he called it "an explosive device," Tukel said.
Tukel added that AbdulMutallab was very verbal and spoke with many people, including some on the flight and officials once the flight landed.
The prosecution also called its first witness Tuesday, Michael Zantow, who was on the flight one row behind AbdulMutallab. Zantow, a 20-year veteran of the Army, was among those who tried to restrain the defendant.
Within a minute of the loud sound on the plane, a passenger said to AbdulMutallab, "Hey man, your pants are on fire!" Zantow testified. The passenger repeated himself two or three times, and AbdulMutallab did not respond, Zantow said.
The jury is made up of three white men and nine women -- six white, two African-American and one Southeast Asian.
CNN's Deborah Feyerick and Laura Dolan contributed to this report.