Paris, who was 11 when her father died, is not available to testify in person in court because she is hospitalized for psychiatric treatment.
While he and his sister no longer want to celebrate birthdays because "it's not the same without" their father, Blanket, now 11, does, Prince said.
"Right now, I don't know if Blanket realizes what he lost," he said. "He was so young. He is still growing up just like I am and he doesn't have a father to guide him."
AEG Live attempted to compel Blanket, the youngest child, to testify, but the judge rejected its request after a psychologist said it would harm the boy.
Changing the world?
Jurors watched a home video of Michael Jackson questioning his three children about how they planned "to change the world" when they grow up.
Prince testified that the video was made at Christmas.
"What's Christmas mean?" Jackson is heard asking his children.
"Love," Blanket responded.
"Who's Blanket going to be to change this world?" Jackson asked.
"I don't know," Blanket, who appeared to be about 5 at the time, answered.
"What does Paris want to do? Be honest search your heart," Jackson said.
"Help the poor," she answered. Paris also said she would like to be a gymnast.
Prince told his father he aspired to be a movie director and architect because he liked "making things."
Private details revealed
Prince, who said his grade point average is 3.68 at the private school in Sherman Oaks, California, at the end of his sophomore year. He is a member of the National Honors Society and received artistic awards at school, he said.
His extracurricular activities include martial arts and working as a mechanic in his school's robotics program, he said. He wants to attend the University of Southern California to study film and business, he said.
His father taught him how "the great ones" made movies, including how to "find shots." He gave him a lens that hung on a necklace that showed what a shot would look like, he said.
Prince said while his school requires a certain amount of community service, he's does more than that. He volunteers at Children's Hospital in Los Angeles in a program that delivers books to young patients "to keep their minds off their problems."
His father "always said you should give back to the community and help out as much as you can," Prince said.
The jury was shown video of Jackson and his children at the Neverland Ranch where they lived until moving after Jackson was acquitted in a child molestation trial.
The family moved after the court case "because there were complications," Prince said. "They ruined it for my dad."
One video showed a giraffe and several alpacas in the Neverland Zoo. "I never really went near them because they would spit on us," Prince said.
The video also showed the carnival rides at Neverland. "We only went there and to the zoo on special occasions because my dad wanted us to remain humble," he said.
When shown a photo of his father sitting with him at a piano, Prince said "I can never play an instrument and I definitely can't sing."