Explain how Mendel was able to disprove what most people believed about inheritance?

Answer 1

Mendel's pea plant experiments showed that at least two types of alleles (dominant, and recessive) must exist. Lets say for example that a red plant (for argument's sake, homo. dominant, RR) is crossed with a white plant (homo. recessive, rr). Most schools of thought at the time would have believed the result of this cross to be pink plants. This is true in some cases, but this was not what Mendel discovered.

Instead, Mendel found the offspring to all the red. The reason?? All of the offspring were heterozygous, meaning they each had one dominant allele, and one recessive allele. (Rr) When this occurs, only the dominant form of the trait (in this case red) will be manifested.

When a red plant and a white plant (for example) are crossed and yield a pink plant, the gene is considered to have "incomplete dominance". There is lots more to learn about simple genetics like this, most of which can be learned in a high school Biology course as well as first year university biology. I suggest you check it out if you are still interested in learning more.