President-elect Joseph R. Biden Jr. said on Saturday that he was “always going to lead with science and truth” as he announced top science and technology officials on his White House staff, reaffirming trust in the kind of expert research that the Trump administration often ignored or disdained.

Extolling what he called “some of the most brilliant minds in the world,” Mr. Biden said his new team’s mission would be to ask: “How can we make the impossible possible?” He vowed to elevate scientific research and thinking on topics like the coronavirus, cancer research, climate change, clean-energy jobs, artificial intelligence, 3-D printing and other fast-advancing technologies.

The appointees included Eric S. Lander, whom Mr. Biden will nominate to be director of the White House Office of Science and Technology Policy, a position that will for the first time hold cabinet rank.

President Trump left the position of science adviser unfilled for 18 months and his administration routinely ignored the guidance of government scientists on issues ranging from the coronavirus pandemic to climate change.

Without specifically mentioning Mr. Trump, Mr. Biden and Vice President-elect Kamala Harris drew an implicit contrast with his administration’s dismissive attitude toward expert opinion.

“The science behind climate change is not a hoax,” Ms. Harris said during the introductions, held at the Queen Theater in Wilmington, Del. “The science behind the virus is not a lie.”

Dr. Lander, who will also serve as presidential science adviser, was a leader of the Human Genome Project. As Dr. Lander’s deputy in the science and technology office, Alondra Nelson, whom was also named by Mr. Biden, is a professor at the Institute for Advanced Study, who has studied the intersection of science with social inequality and race.

Mr. Biden also named two co-chairs of the President’s Council of Advisers on Science and Technology: Frances H. Arnold, the first American woman to win the Nobel Prize in Chemistry, and Maria Zuber, a geophysics and planetary science expert and the first woman to lead a NASA spacecraft mission.

Mr. Biden also said that Dr. Francis S. Collins would remain as the director of the National Institutes of Health.

Earlier on Saturday, the Biden-Harris transition team announced several nominations to the State Department, including that of Brian P. McKeon, who has worked with Mr. Biden for more than 25 years, to be deputy secretary of state for management and resources. Bonnie Jenkins, a veteran arms control expert, was nominated for under secretary for arms control and international security affairs; Ms. Jenkins is also the founder of a group for women of color in national security.

Uzra Zeya, who has held multiple roles at the State Department, was nominated for under secretary for civilian security, democracy, and human rights. Mr. Biden also formally announced the nominations of Wendy Sherman to be deputy secretary of state and Victoria Nuland as under secretary for political affairs; his plans to nominate both Ms. Sherman and Ms. Nuland were previously reported.