genetics

Gregor Mendel was an Austrian monk who revolutionized our understanding and perception of genetics. Mendel’s experiments in his monastery garden provided future geneticists with the basic principles of hereditary through the experimentation in both hybrid and pure bred pea plants, which he found to follow specific patterns in their offspring. The choice to use peas was because of their distinct varieties and their ability to produce offspring quickly and the ability to easily regulate fertilization simply with the use of a paintbrush. When conducting these experiments Before Mendel Pea Plant Experimentation it was commonly accepted that a child’s genetic traits were simply half from the mother and half from the father. This evidence was supported by experiments were generally conducted over a short period of time resulting in skewed and unreliable data, whereas Mendel’s experiments were conducted over an eight year period involving tens of thousands of plants. Two of Mendel’s traits that he focused on were the texture of the seed pod. E.g. smooth and round or wrinkled. In the first generation of these plants 100% of the pea plants possessed the Smooth and round texture. On the second generation of the pea plants of every 4 pea plants 3 posessed the smooth trait and a singular pea plant produced wrinkled seeds. Upon the review of his results Mendel concluded that characteristics could be expressed through dominant and recessive traits. The Dominant trait masks or completely covers the recessive, whereas a recessive gene is an allele that is only present in a homozygous genotype. Through Mendel’s experiments he proposed three principles of inheritance, whether you are looking at humans or pea plants, the apparent genetic traits t...

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... (T), Adenine (A), Cytosine (C) and Guanine (G) In 1953

Joe Hin Tijo is an Indonesian – born American geneticist who has given birth to modern day cytogenetics. Modern Cytogenics was created predominantly when Joe Hin Tijo correctly identified the number of chromosomes present in both human and animal cells. Thus began the study of the numbers, structure and functions of the varying chromosomes. With his research he was able to dismiss a 50 year old belief which was held in the scientific community that in the majority of human cells contained 48 chromosomes, when in fact most human cells only contain 43, 23 from each parent. In 1955 while working in a lab in Sweden he discovered a new way to separate chromosomes from the nucleus of a cell. Furthermore his work resulted in him discovering that people who suffer from Down syndrome possess an additional chromosome.