Mendel and the Laws of Heredity (Part 1)

Gregor Johann Mendel - July 20, 1822 - January 6, 1884

• @@Born in a German@@ speaking family in the Silesian part of the Austrian Empire and gained posthumous recognition as the @@Founder of the Modern Science of Genetics.@@
• Austrian Monk at the Monastery of ==St Thomas in Czech Republic.==
• High School teacher of ==Physics and Natural History.==
• Spent most of his time conducting Biological Experiments.
• Famous on his experiments on ==Crosses of Garden Peas (Pisum sativum) from 1856-1863==

Before Mendel ( Early beliefs about Heredity)

• @@Charles Robert Darwin (1809-1882)@@: English naturalist Darwin introduced the Theory of Natural Selection.
• He expressed his findings and ideas in his famous research publication, =="Origin of Species by Means of Natural Selection"== in the year ==1859==, after observing the living communities of Galapagos Islands.
• Charles Darwin thought that the traits from parents were transmitted to their offspring by BLOOD, thus came the ==blood theory of heredity.== This theory gives rise to the expressions “bloodline” “blue blood” and “blood relative”.
• Early concepts about transmission of traits are now considered inaccurate as we now know that both parents contribute hereditary traits to their offspring and that these ==traits are not contained in blood but in sex cells.==

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Intro to Genetics

• ==GENETICS== – branch of biology that deals with heredity and variation of organisms.
• ==Chromosomes== carry the hereditary information (genes)

1. Arrangement of nucleotides in DNA
2. ==DNA > RNA > Proteins==

• Chromosomes (and genes) occur in pairs==Homologous Chromosomes==
• New combinations of genes occur in sexual reproduction ==Fertilization from two parents==

Mendel’s Experiment (why Garden Peas)

1. Garden Peas have ==several varieties that have observable, contrasting characteristics==

2. Garden Peas ==reproduce by self-pollination== (they reproduce by themselves)

   

Seven Contrasting Traits in Garden Peas observed by Mendel.

Mendel’s Experiment Findings…

• Published these findings in its Scientific journal in 1866 after he reported it to a local natural history society.
• His work was not appreciated until 3 scientists rediscovered his work at around 1900 ==Hugo de Vries, Karl Correns and Erich von Tschermak==
• His achievement was only recognized after the turn of the century, many years after his death

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