Understanding the Phenotypic Variations in Mendel's Pea Plant Experiment
Mendel's experiments with pea plants have provided valuable insights into the principles of inheritance and genetic variation. One of the key observations he made was the appearance of phenotypic variations in the F2 generation, which differed from the parental generation (P). In this article, we will explore the different phenotypes that emerged in Mendel's pea plant experiment and understand their significance. Question 8: In the F2 generation, a phenotype different from the parental generation (P) appears: yellow, wrinkled and green, smooth seeds. These other phenotypes are called: The correct answer is D) mutation. The appearance of phenotypes that are different from the parental generation is a result of genetic mutations. Mutations are spontaneous changes in the DNA sequence, which can lead to alterations in the phenotype of an organism. In this case, the mutation resulted in the combination of yellow, wrinkled and green, smooth seeds, which were not present in the parental generation. Question 9: In Mendel's experiment of crossing two pairs of contrasting purebred traits in pea plants, when analyzing each pair of traits, at F2 the ratio of each pair of traits is: The correct answer is C) 9: 3: 3: 1. This ratio, known as the dihybrid ratio, is a result of independent assortment and segregation of alleles during gamete formation. Mendel observed that when two pairs of contrasting traits are crossed, the phenotypic ratio in the F2 generation follows a specific pattern. In this case, the ratio indicates that for every 9 plants with both dominant traits, there are 3 plants with one dominant and one recessive trait, 3 plants with the other dominant and one recessive trait, and 1 plant with both recessive traits. Question 10: Where is the 2n diploid chromosome set of the species? The correct answer is C) zygote, germ cell, gamete. The diploid chromosome set, which consists of two sets of chromosomes, is present in the zygote, germ cells, and gametes. During sexual reproduction, the zygote is formed by the fusion of gametes, each contributing one set of chromosomes. The germ cells, which are responsible for producing gametes, also contain the diploid chromosome set. In conclusion, Mendel's pea plant experiment revealed the occurrence of phenotypic variations in the F2 generation, which can be attributed to genetic mutations. The dihybrid ratio observed in the F2 generation is a result of independent assortment and segregation of alleles. The diploid chromosome set is present in the zygote, germ cells, and gametes. Understanding these concepts is crucial in comprehending the principles of inheritance and genetic variation.
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