Question
What is the blending theory of inheritance? Why did Mendel question this theory?
Answers
GPT-4o mini
The blending theory of inheritance was a dominant concept in the 19th century that suggested offspring are a smooth blend of their parents' traits. According to this theory, if one parent had a certain trait and the other parent had a different trait, the resulting offspring would have an intermediate characteristic. For example, if a red-flowered plant and a white-flowered plant were to mate, the blending theory would predict that their offspring would have pink flowers. This theory implied that traits would gradually blend and dilute over generations, leading to a loss of variation.
Gregory Mendel, often considered the father of modern genetics, questioned the blending theory through his experiments with pea plants. Mendel carefully tracked the inheritance of specific traits such as flower color, seed shape, and pod color. He discovered that traits are inherited as discrete units, which he called "factors" (now known as genes). Mendel observed that when he crossed different purebred varieties of plants, the traits did not blend but were instead segregated in predictable ratios in the next generation.
For example, when Mendel crossed a purebred tall pea plant with a purebred short pea plant, the resulting offspring were all tall, demonstrating that the tall trait was dominant. When he allowed these tall offspring to self-pollinate, he found a 3:1 ratio of tall to short plants in the next generation, confirming that the traits were segregating and not blending.
Mendel's findings contradicted the blending theory by showing that traits could remain unchanged and segregate independently rather than blend into intermediate forms. This laid the foundation for the laws of inheritance and established the basis for modern genetics.
Gregory Mendel, often considered the father of modern genetics, questioned the blending theory through his experiments with pea plants. Mendel carefully tracked the inheritance of specific traits such as flower color, seed shape, and pod color. He discovered that traits are inherited as discrete units, which he called "factors" (now known as genes). Mendel observed that when he crossed different purebred varieties of plants, the traits did not blend but were instead segregated in predictable ratios in the next generation.
For example, when Mendel crossed a purebred tall pea plant with a purebred short pea plant, the resulting offspring were all tall, demonstrating that the tall trait was dominant. When he allowed these tall offspring to self-pollinate, he found a 3:1 ratio of tall to short plants in the next generation, confirming that the traits were segregating and not blending.
Mendel's findings contradicted the blending theory by showing that traits could remain unchanged and segregate independently rather than blend into intermediate forms. This laid the foundation for the laws of inheritance and established the basis for modern genetics.