 Gregor Johann Mendel is known today as the father of genetics, and he's one of the most famous scientists in history. However, despite his current fame, he actually spent his life in modest anonymity. Gregor Mendel was born on July 22, 1822 in a small village in Czechoslovakia to peasant parents. As a child, Mendel worked as a gardener, where he began his love of science, particularly hereditary science. Eventually, he entered a monastery in Brune, and soon afterwards he began a side project with pea plants, sweet pea plants to be exact. Mendel was incredibly insightful for his time, and even though he was not officially trained to be a scientist, he knew that in order to conduct a proper experiment, several conditions had to be met. First of all, Mendel realized that his plants needed to possess traits that could be categorized into one category or another. He examined things like seed shape, which could be round or wrinkly, and seed color, which could be green or yellow. Secondly, Mendel realized that he needed to start his experiments with what are known as true breeding lines. True breeding plants have been inbred extensively, so that when they're crossed within the line they will have the exact same traits as their parents. Another term that sums this up would be purebred. Thirdly, Mendel picked a plant that would have both male and female reproductive organs, and would be able to either cross-pollinate with another plant, or self-pollinate with itself. This is incredibly important for his experiments, and this is what allowed him to both manipulate his crosses and create true breeding plants. Fourthly, Mendel realized that he needed to replicate his results. This is what allowed him to make sure that they were in fact real and not just coincidence. In this light, he went above and beyond what many researchers do today, and he crossed well over 28,000 plants. Mendel's discoveries were among the first to truly help researchers understand the underpinnings of genetics. Up until this time, most people believed in the blending theory, whereby children were nothing more than a blend of their parents. During Mendel's research, he discovered that, at least in pea plants, there were two copies of genetic material per individual. Now remember, he didn't know about chromosomes back then. He also learned that some traits are dominant over others that are considered recessive. This meant that even though an individual may have a copy of the recessive allele, it will not be expressed while the dominant allele is present. Another discovery that Mendel made that still stands today is known as the law of segregation. This means that the allele separates during the formation of gametes. This is very important, and this explains how children have just the right amount of DNA when both parents contribute genetic information to their offspring. In addition to the law of segregation, was the law of independent assortment. This law says that how alleles separate into gametes is completely random. This was also incredibly important, and it meant that the traits of an offspring are not predetermined, and different combinations of traits are possible. Later in the course, we'll discuss some limitations of this law. Mendel was one of the most influential people, yet he had absolutely no idea regarding what he contributed. His work remained largely unknown until 1900, when his results were duplicated by Hugo de Vries and Karl Karens. Mendel died in 1884. Only then did other scientific community really appreciate Mendel's contributions. Though from that point on, he was known as the father of genetics.