1. Barbara McClintock PowerPoint by Kristina Petersen

2. What was she? • Ms. McClintock was “America’s most distinguished cytogeneticist” • A cytogeneticist= someone who deals with the branch of biology dealing with heredity and cellular components, especially chromosomes. • Chromosome= a circular strand of DNA that contains the hereditary information necessary for cell life.

3. Her Childhood • Born in Hartford, Connecticut on June 16th, 1902 • Spent a lot of time with her aunt and uncle in rural Mass., where she developed a love for the outdoors. • She enjoyed ice skating, playing with neighborhood boys, reading, and thinking. • She moved to Brooklyn, New York when she was eight and attended Erasmus Hall High School there.

4. Formal Education • Ms. McClintock went on to attend Cornell University, where she found her passion for Genetics. • She was asked to take a graduate course while she was still an undergraduate! • Bachelor of Science. • Master of Arts, • Ph. D. • Studied at the Kaiser Willhelm Institute in Berlin in 1933, but returned the following year because of the Nazis. * maize= Indian corn*

5. Her Jobs • From 1927 to 1931 she served as an instructor for the department of botany at Cornell. • Fellow of the National Research Council • Fellow of the Guggenheim Foundation • Research associate in Emerson’s (a professor at Cornell she worked with) department from 1934-1936 • Assistant professor of Botany at the University of Missouri until 1941 • Staff Member and distinguished service member of the Carnegie Institution of Washington • Consultant of the Agricultural Science Program at the Rockefeller Foundation

6. Her Discoveries • Created a method that would let scientists study maize chromosomes and their physical traits at the same time. • Discovered that maize chromosomes exchange genetic material. During meiosis (cell division) • Discovered nucleolar chromosomes. • Thought that genes might explain the unusual rapid creation of a new species of plant or animal. • Genetic Transposition- what she was most famous for.

7. Genetic Transposition • Genetic Transposition= the process where a gene can go from one position on a chromosome to a new position. • The genes involved are called “jumping genes” • She saw different colored spots that didn’t belong on green or yellow leaves of a certain plant. • She concluded that the larger the patch of discoloration, the early the mutation occurred. • From her discoveries, she found that one of a plant’s offspring “could have an unexpected pattern of heredity” due to a certain genetic code that the other one did not possess. • When she first published this idea in 1950, many didn’t accept it, as it completely contradicted the current popular theory that genes were stable components of chromosomes. • It was more widely accepted in the 1970’s, when geneticists were able to study genes on a molecular level.

8. Awards Received by Ms. McClintock • 15 different awards from various places all across the country, and from different parts of the world • 12 honorary doctors of science from various colleges and universities • Honorary Doctor of Humane Letters. • Finally, she received the NOBEL PEACE PRIZE in 1983 for her discovery of mobile genetic elements.

9. Her Nobel Peace Prize • Eighty-one years old • 32 years after the discovery she was awarded for was made • third woman to be awarded an individual prize in the sciences. • “The prize is such an extraordinary honor. It might seem unfair, however, to reward a person for having so much pleasure, over the years, asking the maize plant to solve specific problems and then watching its responses.”

10. Her Influence on Science • Without some of her discoveries, we wouldn’t know some of the things we do about genetics today. • For example, how resistance to antibiotic drugs can be passed from one kind of bacteria to another through jumping genes was found through using a lot of what McClintock discovered. • Her studies also led to the discovery of genetic imprinting, or the presetting of genetic activity. • She also inspired many other women scientists to pursue their dreams, as she was working in the field of science when women were still considered inferior, and a women scientist like herself wasn’t a particularly accepted figure in society. • “Her discovery opened the door to the integration of plant-breeding experiments with chromosomal analysis.”- http://vnweb.hwwilsonweb.com/hww/results/results_single.jhtml?nn=9

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12. Bibliography • November 19, 2003 http://vnweb.hwwilsonweb.com/hww/results/results_single.jhtml?nn=9 • McClintock, Barbara. “Barbara McClintock-Autobiography” Nobel e-Museum November 17, 2003 <Http://www.novel.se/medecine/laureates/1983/mcclintock-autobio.html> • “Barbara McClintock” National Women’s Hall of Fame- Women of the Hall November 18, 2003 <http://www.greatwomen.org/women.php?action=viewone&id=106> • November 20, 2003 <http://vnweb/hwwilsonweb.com/hww/results/results_single.jhtml?nn=7> • Peggi Saari and Stephen Allison, ed. Scientists- The Lives and works of 150 Scientists, Volume 2 U.S.: An Imprint of Gale. 1996, 625-627