Gregor Mendel
Date of Birth: July 20th, 1822 in Czech Republic
Date of Death: January 6th, 1884 in Czech Republic
Profession: Scientist and Friar
Facts about Gregor Mendel:
1. Mendel decided to join the monastery
because his family was poor.
2. According to Mirrornews, Mendel was
born into a German family in the
Austrian Empire (modern day Czech
Republic).
3. Between 1856 and 1863, Mendel
experimented on about 29,000 pea plants.
4. He is the founder of the new science of genetics.
Mendel’s Friends:
Charles Darwin:
-Darwin was an English geologist. He was most known for his
contributions to the evolutional theory.
Sigmund Freud:
-Freud was an Austrian neurologist. He was best known for his theories of
psychoanalysis.
Louis Pasteur:
-Pasteur was a French microbiologist and chemist who studied bacteria.
Why Pea Plants?
Gregor Mendel decided to select his work and experiment on peas for
several reasons. At first, it is thought that he wanted to breed animals
instead but because the superior monks who lived in the monasteries
thought that it was inappropriate, he decided to experiment with peas. The
peas were very fast at growing so he could experiment on them easier. The
second reason was because the peas’ traits were easy to contrast and they
were identifiable. As he used many pea plants it was affordable to grow
easily outside.
The Traits
Heredity is when a trait is passed on from parents to offspring (which are
children). Mendel experimented on certain traits of peas. He spent 7 years
breeding and growing peas. Whenever Mendel was studying, he always
studied the purebred plants first. Purebred plants ALWAYS produced an
offspring with the same trait as the parent generation. Mendel first
wondered why different pea plants had different characteristics, why some
of the plants were tall and why some of them were short, why some of
them had green seeds and why some of them had yellow seeds. Each
different form of a characteristic, such as the stem or height are called
traits. Mendel did not only crossbreed one plant, he also crossed with other
pea plants with other contrasting traits. Traits are controlled by the alleles
that we inherit from our parents; the dominant allele and the recessive
allele. We inherit both dominant and the recessive trait. The dominant trait
is stronger than the recessive trait, which means it will always show up in
the organism, where the recessive trait is ‘hiding’ behind the dominant. To
get a trait that is controlled by the recessive trait, there could be no
dominant alleles. For pea plants, Mendel studied and discovered the
several traits.
Fertilization of the Pea Plants
Self-fertilization is also called self-pollination where a new organism
begins to form. Mendel used a brush to remove pollen from a white flower
onto another plant (purple flower). This process is called cross- pollination.
Mendel cross- pollinated or ‘crossed’ pea plants. Mendel waited upon
many generations for a purebred organism that have the same trait.
(Picture above). If Gregor Mendel did not discover how the pea plants selfpollinated or cross- pollinated it would have taken longer to know that
there is a 𝐹! generation and a 𝐹 ! generation and the details and the cause
in why there are different traits passed on.
Parent Generation
The parent generation is also known as the P generation. Mendel first had
to produce a set of purebred plants to start cross- pollinating with other
plants. Without the parent generation, Mendel’s calculations and outcomes
would be entirely different. The parent generation was used for first crosspollination, which led to the 𝐹! generation.
𝑭𝟏 Generation
The offspring (children) from the parent generation is called the
𝐹! generation, also known as the first filial. The ‘F’ in 𝐹! stands for ‘filial’ or
‘filius’, which in Latin words means ‘son’ or ‘daughter’. The 𝐹! generation,
after many retries, always had a result of having purple flowers, even
though the white and purple flower was crossed. It seemed to Mendel that
the white flower had just magically disappeared! As the 𝐹! generation had
both dominant and recessive alleles (but you couldn't see the recessive)
they were all hybrids. 𝑭𝟐 Generation
After the plants were fully grown, Mendel let the 𝐹! generation plants to
self- pollinate. To his surprise, the 𝐹 ! generation were a mix of white
colored flowers and purple colored flowers. We can generally say that the
white flower had reappeared even after the 𝐹! generation did not have any
white flowers. The interesting outcome is that Mendel experimented the
cross and self- pollination with the other traits and he got the same result;
he got a ratio of 3:1. Out of the 4 flowers in the 𝐹 ! generation, 3 of them
were purple (dominant) and 1 was white (recessive).
Fundamentally, the purple flower was able to cover up the white flower
during the 𝐹! generation. That means that the purple flower was the
dominant (which means covers the recessive in the 𝐹! generation) and the
white flower was the recessive (the ‘hiding’ flower in the 𝐹! generation).
Reviews from Peers
Just like Alfred Wagner and his theory for Pangaea, Mendel’s peers rejected
his work with peas and ‘factors’, which are now known as genetics.
Mendel’s discoveries eventually changed scientists’ ideas about heredity
and genes. Most of the scientists before Mendel, thought that the
individual organisms were just a blend when they were crossed. For
example, they thought that if one flower had a color of white and the other
flower had the color of dark blue the offspring would have a color of light
blue. In spite of that, Mendel was determined to show them that they were
wrong. He justified that the individual organisms were not ‘mixed’ nor
‘blended’. Unfortunately, his discovery was not recognized during his
lifetime. There were 3 scientists that re- discovered Mendel’s work: Hugo
DeVries, Carl Correns, Erich von Tschermak. The three scienctists, who did
not know each other, were working on different plant hybrids. When they
worked out the laws of inheritance for the plants, they reviewed the work
that was done by other people before publishing their own, and found
Mendel’s work in full detail. Mendel’s work was a support for their theories
and was a confirmation.
Comments:
*Charles Darwin commented on Gregor Mendel’s post*
“I am so very happy that somebody justified my work. Now I can really rest
in peace. I hope you had a great time learning about heredity and
discovering the laws of genetics. I am excited to see how all our work
combined will affect the future”.
*Christian Doppler commented on Gregor Mendel’s post*
“As your teacher in university I am proud to say that you were the best out
of my class. You have certainly impressed me with your work even though
you didn't during the years you were in university. Good luck”.
Gregor Mendel Google doodle: 10 things you need to know about the scientist. (n.d.). mirror. Retrieved
March 2, 2014, from http://www.mirror.co.uk/news/uk-news/gregor-mendel-google-doodle-10183520
Science in the 1800's. (n.d.). Science in the 1800's. Retrieved March 3, 2014, from
http://powpak.allencountyesc.org/powpak/cgi-bin/lp_display_page.pl?id=cook_c&lp=1
Pea traits [Image]. (n.d.). Retrieved from http://www.goldiesroom.org/
Note%20Packets/18%20Genetics/00%20Genetics--WHOLE.htm
Biology for Kids. (n.d.). : Mendel and Inheritance. Retrieved March 4, 2014, from
http://www.ducksters.com/science/biology/ Online Education Kit: 1900: Rediscovery of Mendel's Work. (n.d.). Online Education Kit: 1900:
Rediscovery of Mendel's Work. Retrieved March 3, 2014, from http://www.genome.gov/25520238 Gregor Mendel. (n.d.). Gregor Mendel. Retrieved March 4, 2014, from
http://www.nndb.com/people/015/000083763/
Gregor mendel [Image]. (n.d.). Retrieved from Gregor Mendel. (n.d.). Gregor
Mendel. Retrieved March 4, 2014, from http://www.nndb.com/people/015/
000083763/