Barbara McClintock, Geneticist and Nobel Prize Winner - March 14, 2025

0:01American Barbara McClintock is considered one of the most important scientists of the 20th century. Her discoveries about genes and chromosomes led to her winning the Nobel Prize for Physiology or Medicine in 1983. McClintocke was born in 1902 in Hartford, Connecticut. She was the third of four children. She an active child with interests in sports and music and developed an early McClintock decided to study botany, the scientific study of plants, at New York's Cornell University. She completed her undergraduate studies in 1923 and continued on to complete a master's degree in 1925, and two years after that she was awarded a doctorate degree. After finishing her studies, McClintack decided to stay at Cornell to teach botany.

1:10She also supervised genetic studies of the corn plant, and she studied the behaviors of chromosomes. A chromosome is the part of a cell that controls what an animal or plant is like. McClintock began to study the way genes react to unusual events. While looking at corn treated with radiation, she identified unusual areas she called ring chromosomes. She believed these were chromosomes broken by radiation. The broken ends sometimes joined together and formed a circle or ring. This led her to believe that a structure at the end of the chromosome prevents chromosomes from changing. She called this structure the telomere. In 1941, McClintock began working at the Cold Spring Harbor Laboratory, a research center

2:11near New York City. In her work, she found that some corn plant genes acted unusually. This led her to develop a theory. McClintock believed the movable genes were not genes at all, but genetic controllers or controlling elements. She found they could influence the actions of other genes. In 1944, McClintocke was elected to the National Academy of Sciences. She was the third woman to receive that honor. She was also named President of the Genetics Society of America. But some other scientists reacted to her ideas with a mixture of criticism and silence. For years, many scientists dismissed McClintock's findings. Her work at Cold Spring Harbor Laboratory was finally recognized in 1970. That is when she was given the American government's highest science award, the National Medal

3:19of Science. During the 1970s, newly developed methods in molecular biology confirmed what McClintock had learned through her observations. Her discoveries influenced everything from genetic engineering to cancer research. McClintoc won the Nobel Prize for Physiology or Medicine in 1983. She was recognized for her discovery that genes were able to change positions on chromosomes. She was the first American woman to win an unshared Nobel Prize. Barbara McClintock remained at Cold Spring Harbor for the rest of her life. She died in 1992 at age 90. I'm Jill Robbins.