Mendel, In One of His Experiments with Pea Plants, Crossed A Variety of Pea Plant Having Round Seeds with One Having Wrinkled Seeds. State Mendel Observations Giving Reasons of F1 and F2 Progeny of This Cross. Also, List Any Two Contrasting Characters, Other Than the Round Seeds of Pea Plants That Mendel Used in His Experiments.


Introduction

Gregor Johann Mendel was an Austrian monk and botanist, who is widely regarded as the father of modern genetics. He is credited with laying the foundation of genetics as a scientific discipline, through his experiments with pea plants, in which he demonstrated the principles of inheritance.

One of Mendel's most famous experiments involved crossing a variety of pea plants having round seeds with one having wrinkled seeds. This experiment, which he conducted between 1856 and 1863, helped him to discover the fundamental laws of inheritance, which later became known as Mendelian genetics.

Mendel's Experiment with Pea Plants

Mendel's experiment involved crossing two purebred pea plants, one with round seeds (RR) and the other with wrinkled seeds (rr). These are referred to as the parent or P generation. Mendel then observed the traits that were expressed in the offspring, which are referred to as the first filial or F1 generation.

The results of the experiment were surprising. Instead of producing offspring with intermediate characteristics, as was expected, all the offspring had round seeds, which were the dominant trait. The ratio of round to wrinkled seeds was 3:1, indicating that three-quarters of the offspring had the dominant trait, while one-quarter had the recessive trait.

Mendel then allowed the F1 generation to self-fertilize and produce the second filial or F2 generation. The results of this cross were also surprising. Mendel observed that the ratio of round to wrinkled seeds in the F2 generation was also 3:1, the same as in the F1 generation.

Mendel's Observations

From his observations, Mendel concluded that the traits of the parents are not blended in the offspring, but instead, each trait is inherited separately. He also discovered the concept of dominant and recessive traits. In the case of the pea plants, the round seed trait was dominant, while the wrinkled seed trait was recessive.

Mendel explained the results of his experiment using the laws of segregation and independent assortment. According to the law of segregation, each individual has two alleles for a given trait, which separate during the formation of gametes. Therefore, each gamete carries only one allele for a given trait. When fertilization occurs, the offspring receives one allele from each parent.

The law of independent assortment states that the inheritance of one trait is independent of the inheritance of another trait. This means that the alleles for different traits are inherited randomly and are not influenced by each other.

Two Contrasting Characters Used by Mendel

Apart from the round and wrinkled seed traits, Mendel used many other contrasting characters in his experiments. One of these was flower color, which is either purple or white. The purple color is dominant, while the white color is recessive.

Another contrasting character used by Mendel was the flower position. In some pea plants, the flowers are located at the top of the stem, while in others, they are located on the sides. The top position is dominant, while the side position is recessive.

Conclusion

Mendel's experiment with pea plants was ground-breaking in the field of genetics. Through his careful observations and analysis, he discovered the fundamental principles of inheritance that govern the transmission of traits from one generation to the next.

His work laid the foundation for modern genetics, and his principles are still used today in the study of genetics and heredity. Mendel's legacy continues to inspire scientists and researchers in their pursuit of knowledge and understanding of the natural world.

Updated on: 19-May-2023

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