Barbara McClintock, Geneticist and Nobel Prize Winner

01American Barbara McClintock is considered one of the most important scientists of the 20th century.

02Her discoveries about genes and chromosomes led to her winning the Nobel Prize for Physiology or Medicine in 1983.

03McClintock was born in 1902 in Hartford, Connecticut.

04She was the third of four children.

05She was an active child with interests in sports and music and developed an early interest in science.

06McClintock decided to study botany, the scientific study of plants, at New York's Cornell University.

07She completed her undergraduate studies in 1923 and continued on to complete a master's degree in 1925.

08And two years after that, she was awarded a doctorate degree.

09After finishing her studies, McClintock decided to stay at Cornell to teach botany.

10She also supervised genetic studies of the corn plant.

11And she studied the behaviors of chromosomes.

12A chromosome is the part of a cell that controls what an animal or plant is like.

13McClintock began to study the way genes react to unusual events.

14While looking at corn treated with radiation, she identified unusual areas she called ring chromosomes.

15She believed these were chromosomes broken by radiation.

16The broken ends sometimes joined together and formed a circle or ring.

17This led her to believe that a structure at the end of the chromosome prevents chromosomes from changing.

18She called this structure the telomere.

19In 1941, McClintock began working at the Cold Spring Harbor Laboratory, a research center near New York City.

20In her work, she found that some corn plant genes acted unusually.

21This led her to develop a theory.

22McClintock believed the movable genes were not genes at all, but genetic controllers or controlling elements.

23She found they could influence the actions of other genes.

24In 1944, McClintock was elected to the National Academy of Sciences.

25She was the third woman to receive that honor.

26She was also named president of the Genetics Society of America.

27But some other scientists reacted to her ideas with a mixture of criticism and silence.

28For years, many scientists dismissed McClintock's findings.

29Her work at Cold Spring Harbor Laboratory was finally recognized in 1970.

30That is when she was given the American government's highest science award, the National Medal of Science.

31During the 1970s, newly developed methods in molecular biology confirmed what McClintock had learned through her observations.

32Her discoveries influenced everything from genetic engineering to cancer research.

33McClintock won the Nobel Prize for physiology or medicine in 1983.

34She was recognized for her discovery that genes were able to change positions on chromosomes.

35She was the first American woman to win an unshared Nobel Prize.

36Barbara McClintock remained at Cold Spring Harbor for the rest of her life.

37She died in 1992 at age 90.

38I'm Jill Robbins.

39I'm Jill Robbins.