Intro:
In the 1800’s, a hypothesis existed that suggested that genetic material is contributed by the two parents by mixing an equivalent way. However, this “blending hypothesis” did not last long due to the discovery that if this had been true, we would end up with a uniform population of individuals. Gregor Mendel, a scientist and monk, documented a particulate mechanism for inheritance. This was developed before chromosomes were observed under the microscope, and at this point in time, no one understood how they worked. Mendel discovered the basic principles of heredity by breeding garden pees in carefully planned experiments. He chose to work with peas, because they come in several varieties and had many different traits about them. Mendel was focused on controlling mating between the plants (Campbell). Through the selective cross-breeding of common pea plants (Pisum sativum) over many generations, Mendel discovered that certain traits show up in offspring without any blending of parent characteristics. Each variety has a different color flower, one purple and one white. This flower color varies among each individual and is called character. The reproductive organs of a pea plant are in its flowers, and each pea flower has both pollen-producing organs (stamens) and an egg-bearing organ (carpel). Although, in nature, pea plants self-fertilize, Mendel altered the flowers so he could always be sure of the parentage of the new seeds.
Purpose:
The purpose of this experiment is to determine how inherited characteristics are passed down through generations. By observing factors, such as flower color, flower position, seed color, seed shape, pod shape, pod color, and stem length, many hypothesis’ could be made. Mendel was attempting to follow how traits change as they move from generation to generation.
Procedure and Materials:
First, Mendel would remove stamens from the purple flower. Next, he
Cited: Campbell, Neil A. “Mendel and the Gene Idea.” AP Edition Biology. 8th ed. San Fransisco: Pearson Education, 2009. 262-81. Print Pitman, Sean D., MD. “Gregor Mendel – Father of Genetics.” Gregor Mendel – Father of Genetics. Detecting Design, May 2002. Web. 14 Jan. 2013.