We have known for centuries that traits are passed from parents to offspring. What has not always been understood is how traits are determined. One explanation that has fascinated scientists for many centuries has been that the traits of the parents were mixed or blended in the offspring. The fusion hypothesis explained many observable traits and was widely accepted for many years. However, the idea of ​​fusion could not explain the appearance of unexpected traits in some descendants. It was only when scientists discovered the cellular basis of life that the inheritance of traits was better understood. The first clues to understanding heredity came from Gregory Mendel, one of the most eminent scientists in the field of genetics. Mendel, an Austrian monk, began his work in the 1860s. He used pea plants to study how traits were passed from one generation to the next. The structure of the pea flower allowed Mendel to isolate an important variable, fertilization. In fertilization, the male plant gamete, located at the base of the pistil. The relatively closed structure of the petals of the pea flower makes it very easy for pollen from the anther to fertilize the pistil of the same flower. This process is called self-fertilization. If a plant or any organism receives the same genetic traits from both its parents, it is said to be purebred. Self-fertilization produces purebred pea plants. As you can see Mendel also altered plants and transferred pollen by hand. By controlling pollination and preventing self-fertilization, Mendel crossed plants, producing hybrids. A hybrid is an organism that receives different forms of a genetic trait from each parent. Garden pea plants have some easy-to-see traits, which allowed Mendel to produce observable results. Mendel studied seven traits. Each of these traits is unusual in that it has only two distinct forms. For example, pea pods are yellow or green. There is no intermediate or gradient color. The height of the plant is high or low, never medium. Distinct traits like this are rare in nature, as you'll see later in this unit. The distinctive traits of pea plants allowed Mendel to see his results without guesswork. Another important feature of pea plants is that most plants reproduce in about 90 days. The short breeding cycle gave me...... middle of paper......, it's called purebred. Self-fertilization produces purebred pea plants. As you can see Mendel also altered plants and transferred pollen by hand. By controlling pollination and preventing self-fertilization, Mendel crossed plants, producing hybrids. A hybrid is an organism that receives different forms of a genetic trait from each parent. This process is called self-fertilization. If a plant or any organism receives the same genetic traits from both its parents, it is said to be purebred. Self-fertilization produces purebred pea plants. As you can see Mendel also altered plants and transferred pollen by hand. By controlling pollination and preventing self-fertilization, Mendel crossed plants, producing hybrids. A hybrid is an organism that receives different forms of a genetic trait from each parent. When Mendel let F hybrid plants self-fertilize, he discovered that things are not always as they seem and even if they are, then you will have to see and see me clearly. Instead, Mendel found that all those F hybrid plants contained yellow peas. In the first generation of pea plants there were neither green nor chartreuse peas, even though one of the mother plants had green peas.