A former Bronx Science biology teacher and her boyfriend drove to the middle of the Tappan Zee Bridge yesterday, emerged naked from their car and, holding hands until the last second, jumped in a bizarre suicide mission, cops said.

Alfa Choice, 29, was pulled from the churning Hudson River alive but died shortly after. Her boyfriend, Christopher Shears, 44, incredibly survived the plunge and was unconscious in the intensive-care unit at Nyack Hospital.

He’s expected to survive but may be paralyzed, authorities said.

“I have friends here to support me,” said his mother, Cassie Dee Shears, who visited him in the hospital last night. “He’s not doing better.”

When asked if her son had been upset about anything, the woman said, “I don’t know.”

Friends said yesterday that Choice was a gifted student at the Bronx HS of Science and attended Cornell University as an undergrad before returning to her high school as a teacher. She had been on a leave of absence from grad-school studies.

She was dating fellow Bronx native Shears and the two lived together in Ithaca.

As they stood on the edge of the bridge, it appeared for a moment that Choice had a sudden change of heart, sources said.

Staring at the 175-foot drop, Choice hesitated. Cops are looking into the possibility that Shears, determined not to go alone, may have pushed her off — and then jumped himself.

He could be charged in her death, the sources said.

“We’re still investigating,” said State Police investigator Skylar King.

Witnesses saw them halt their Chevy Tahoe in the right, southbound-bound lane of the bridge shortly after 9 a.m.

With traffic backing up behind them, they got out of the SUV together, completely naked, and climbed atop the vehicle.

Using that height advantage, they then climbed over the bridge’s five-foot-high suicide-prevention fence and reached a shorter railing, said Joseph Becerra, another State Police investigator.

Witnesses saw them holding hands and staring down into the Hudson.

That’s when Choice, who taught at Bronx Science from 2004 to 2007, hesitated and was perhaps shoved, sources said.

Construction workers at the base of the bridge scrambled to pull the duo from the water.

“His eyes were open, but there were no words,” one worker said of Shears.

At her former apartment building in Ithaca, those who knew Choice were stunned at her death.

“She was not a person I would think would commit suicide,” said one resident, who added that Choice — who frequently dressed in black — was often visited by women, also donned in black, that she introduced as her “sisters.”

The neighbor once asked Choice if she were a nun and she said, “No.”

Police sources said Choice may have belonged to a cult.

Public records show that Choice had more than $10,000 in liens and judgments against her.

Additional reporting by Ikimulisa Livingston and Jennifer Bain

larry.celona@nypost.com

