Gregor Mendel

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Gregor Mendel, born 1822, was an early genetic biologist [1]. He is now considered 'the father of modern genetics' for his contributions in discovering the way in which genetic traits are passed from generation to generation. His experiments with pea plants established the fundamental principles used in modern genetics; namely the Law of Segregation and the Law of Independent Assortment. Mendel found, through his pea plant experiments, that there are dominant and recessive traits in the genes of organisms and that these traits are passed on statistically from generation to generation [2]. You will often read about 'Mendelian' genetics - this is referring to the work done by Gregor Mendel.

In the 18th century, before Mendel’s investigation, it was thought that the reason why parents’ traits were inherited by offspring was due to the mixture of liquid in the sperm and ovum. However, Mendel Gregor made a hypothesis that traits were coming from a gene, thus investigating the features of pea, and discovered some laws which became the base of every genetic field. The first law is the Law of Dominance, in which one allele is more dominant than the other allele when the pair of alleles come from the parents. Therefore, a strong allele, called a dominant allele, makes the phenotype show the property of that allele, while the other weak allele, called a recessive allele, has no affect on the phenotype even though it is in the gene. The second law is the Law of Segregation, in which the pair of parents’ alleles are divided from each of them and only one allele comes from each parent is passed to the offspring [3]. Nowadays, this process is called “meiosis”, the cell division of sex cell. The third law is the Law of Independent Assortment states that a different pair of alleles come from each parent to their offspring independently thus resulting in new types of genes which are not even present in the parents’ genes. For example, if a purple colour allele of the flower comes from one parent, and a white colour allele of the flower comes from the other parent, there is a possibility there can be a pink coloured flower in the first generation of those two parents.

References.

  1. Gregor Johann Mendel. 2014. The Biography.com website. [Internet] Available from: http://www.biography.com/people/gregor-mendel-39282 [Accessed 27 Nov 2014].
  2. Sturtevant, A. H. (1965). A HISTORY OF GENETICS. New York, U.S.A.: Harper and; Row. p9-11.
  3. University of Leeds. (2015). Learning the right lesson from Mendel's peas. Available: http://phys.org/news/2015-10-lesson-mendel-peas.html. [Last accessed 26th Oct 2017].
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