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Gregor Mendels Pea Experiment

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Gregor Mendel (1822- 1884) was known as the "Father of Genetics" (2006, Gregor Mendel). Before Gregor came along, the process of hybrids and inheritance was not known by many people (O’Neil, 2006). It was between the 1980's and the 1990's that new inventions arose and enabled scientists to understand concepts like cell division and sexual reproduction (O’Neil, 2006). It was between the years of 1858 and 1863 that Gregor began his first genetic experiment on pea plants, this experiment would be one that he would be remember for forever through “Mendel’s Laws of Inheritance (2006, Gregor Mendel).

Mendel’s pea experiment was done through selective cross breeding of pea plants also known as Pisum sativum (O’Neil, 2006). After years of testing his theory of cross breeding on pea plants, he finally came to the conclusion that certain traits appear in the offspring of an organism without “blending” a parent’s characteristic (O’Neil, 2006). The pea plants the Mendel tested were either purple or white. When Mendel observed the traits he concluded that they only occurred in two forms (O’Neil, 2006):

The flower colour is purple or white
The flower position is axil terminal
The stem length is long or short
The seed shape is round or winkled
The seed colour is yellow or green
The pod shape is inflated of constricted
The pod colour is yellow or green


(above is a diagram of the first and second generation of pea plants that Mendel modified)

This observation was very useful to scientists and proved many things dealing with genetic modification. These observations lead to the proof that traits do not show up in the offspring plants (O’Neil, 2006). This lead to many theories in biology, and proved the theory wrong that inherited traits continue on and blend from one generation to the next (O’Neil, 2006).

Mendel’s Pea Experiment

The organism that was being experiment on was a garden pea plant. Garden pea plants are grown in large amounts and their reproduction cycle is easy to manipulate (O’Neil, 2006). Another characteristic about pea plants are that they carry both male and female reproductive organs and can self pollinate or cross pollinate to produce more(O’Neil, 2006). Mendel successfully cross pollinated the pea plants and this became the base for genetic inheritance (2006, Gregor Mendel). After years and years of extensive research and continuous experiments, Gregor Mendel came up with a number of conclusions. These conclusions were that (O’Neil, 2006):

Inheritance is determined by genes
An individual inherits one gene from one parents and another from the other parent
Traits may not show up in an individual but they can however be passed on to another generation

Mendel also came up with two principles (O’Neil, 2006): the principle of segregation (2006, Gregor Mendel) and the principle of independent assortment.

Principle of Segregation

This principle states that different allele pairs are passed onto offspring independently of one another. It is a rare chance that a pair of alleles is inherited from a parent (O’Neil, 2006). These pairs of alleles unite in fertilization (Bailey, 2006).

Principle of Independent Assortment

Is where different pairs of alleles are passed to offspring and this is done independently (Bailey, 2006). The final result of this happening is that new combinations of genes are present have the ability to not be seen in the parent of the offspring at all (O’Neil, 2006).

In conclusion, Mendel’s work did not appear until the 20th century. However, his research was the foundation of genetics (2006, Gregor Mendel). Many scientists go back to Mendel’s experiments today to collect research and gain understandings.



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To get a better idea of the process that Mendel went through in his pea experiment, visit the following interactive website: http://biologica.concord.org/webtest1/web_labs_mendels_peas.htm.

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