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TERRY DOES SCIENCE!
GENETICS
How many times have you heard the expression - She has her mother's eyes? Or He has his father's nose? Of course they DON'T have the mother's eyes or the father's nose. What they have are very similar to the parents but not the exact same. How does this happen?
It's all down to Genetics, and the father of Genetics is Gregor Mendel.
Mendel was born in 1822. During his childhood, he took a keen interest in gardening and beekeeping. He decided on becoming a monk and hoped to eventually become a teacher. He went to the University of Vienna but never actually managed to pass his exams, so he returned to the monastery a failure. He now had to decide what to do. While he was at University, he developed an interest in experimental biology and surprisingly he was allowed stay on and do his experiments because at this time, the monks weren't even allowed to teach Biology.
For many years he experimented with pea plants. The first couple of years were spent purifying his stock and he then undertook his experiments. These were quite simple experiments. He crossed Tall Pea plants with small pea plants and was surprised with the results. Rather than getting a mixture? or dilution of each parent, in this case, medium sized plants, ALL his offspring were tall. The same happened for every trait he chose. The resulting offspring were ALWAYS like one parent and never a mixture of both. Mendel referred to this as the dominant trait and the trait that disappeared he called the recessive trait.
He then allowed his offspring to self-pollinate and then he got his second surprise. His recessive trait, the one that had disappeared now reappeared in the second generation, but more importantly, because Mendel worked with large numbers of plants, literally thousands of them, and because he was a keen mathematician, he noted that there was a definite ratio of dominant to recessives in the second generation. He published his results in 1866 - and they made no impact whatsoever. In fact they lay undisturbed for over 30 years.
Mendel continued with his work. His intention was to progress his experiments from plants to animals.
Because of his earlier interest in bees he decided to work with them. He bred about 50 bee races, which he tried crossing to get new breeds. He did manage to produce a hybrid strain of bees which produced excellent honey, but unfortunately they were so vicious that they stung everybody for miles around. As you can imagine this made him very unpopular with the locals.
Shortly afterwards Mendel was made Abbott. This meant more time had to be spent on the running of the monastery and gradually his experiments came to a halt. He died in 1884.
An unusual thing happened after his death. The next Abbott decreed that all Mendels belongings and papers be brought out into the courtyard and burned. No one knows for sure what he did to irritate his new boss, but what it meant was that all Mendels experiments, ideas and results were lost.
All that was left was his original paper from 1866 and this was rediscovered in 1900 by a number of geneticists but it wasn't until the 1920?s and 1930?s that the full significance of his work, particularly in relation to evolutionary theory was appreciated. Mendel had died without realising the importance of his work. In memory of his achievements, he is recognised as the father of genetics.
The reason why we resemble both our parents is due to sexual reproduction. We get half our genetic information from each parent, half in the father's sperm and half in the mothers egg. ? Each parent carries one copy of information and at fertilisation both these sets are combined. Mendel understood this simple fact and this allowed him to devise? the simple crosses that he undertook.
His discovery was highly significant because it allowed scientists to finally understand the mystery why children ended up looking very similar to their parents, but not exact replicas. It helped them understand that heredity is at the heart of development.
Mendels findings are the basis of the science of Genetics.
Just before his death, he commented: My scientific labours have brought me a great deal of satisfaction, and I am convinced that before long the whole world will praise the result of these labours?
How right he was.!
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