Barbara McClintock

Biography

Born on June 16,1902 in Hartford, USA
Her father was working as a family Doctor. He was well known and some family came to USA from Britain to reach him.
1908, whole family moved to Brooklyn, New York
1919, in spite of her mom rejected her to go to university, Barbarastated to go to Cornell University which she gained a lot of experiences.
1925, she was awarded an M.S in botany
1927, she was awarded an P.h.D. in botany
after completed her courses, she became in instructor in the Botany Department

Her research

In 1931, she founds out the chromosomal crossover

(also known as Transposon)which was her major discovery.

She was the first person to see the chromosomes clearly

under the microscope with cellular size. Since she could see the

chromosomes clearly, she could prove that chromosomes have

chromosomal crossover. Chromosomal crossover happens when

the cell starts the process of meiosis. Egg and sperm are haploid

cells which only contain half the normal number of chromosomes.

When the egg and sperm cells which have 23 chromosomes each

merges, it creates a new cell with 46 chromosomes. Due to this

reason, she discovered that during the process of merging, the cells

can shuffle the genetic information to produce chromosome variations.

Even though chromosomal crossover had been discovered by Thomas

Morgan, she was the first person to prove this theory with the corns

In the beginning of 1944, she studied deeper relationship of the chromosomes. To have the better explanation of jumping chromosomes, she looked closer at maize chromosomes. She puts a lot of effort on making visible image of maize chromosomes. This will be used in the textbook later on, and many students who studies genetics will learn method. She developed the way to show the changing colour of chromosomes using Acetocarmine. From this method, she proved the 10 different chromosomal composition of the maize.

Her prove of the different chromosomal composition of the maize help to develop the genetic linkage. She has recieved a Nobel prize.

*Transposon - changing position within the chromosome which can cause mutations

example of genetics selection

There are no human existing who has the exactly same gene and the gene order. they all look different due to the chromosomal crossover which has been proven by the Barbara McClintock.

Chromosomal crossover happens when the cell starts the process of meiosis. In the human process, it’s the process when the egg and sperm merged together. During the process of merging, the both of the haploid cells provide the information of the gene to create the complete human chromosome. Those crossing over are random and we still cannot predict with our technology and skills.

The crossover of the chromosomes are random, but they are essential factor when the organisms are creating the new life.

Benefit to human?

From her findings of Transposon, we now can be aware of happening of the chromosomal crossover. After this was discovered, the medical sciencemedicine improved much faster and easier. People could not understand the chromosomal crossover, which was the most important thing to understand when the genes are concerned. From her clear evidence of maize, the people who are in the medical sciencemedicine field have better understanding of it and be aware of those happening.