Question

What hereditary factors were described by Mendel?

Answer 1

Gregor Mendel is called the Father of Genetics. He worked on experiments involving the simple hybridization of Pisum sativum that he had planted in his garden.

Complete answer:
Mendel chose traits that had two forms for his hybridization experiments for Garden Pea. Those traits were:
-Pea shape- round or wrinkled
-Pea colour- yellow or green
-Flower position- terminal or axial
-Flower colour- purple or white
-Plant height- tall or short
-Pod colour- yellow or green
-Pod shape- inflated or constricted
Based on these factors, Mendel devised his principles of inheritance.
1. Law of Dominance:
According to Mendel’s law of dominance, if two parents who differ in one genetic characteristic for which they are homozygous mate with each other, then all offspring produced in the F1 generation will exhibit the dominant trait.
A study between the crosses of a couple of 4o’clock plants, Mirabilis jalapa shows an exception towards Mendel’s Law of Dominance. It is called Incomplete Dominance
2. Law of Segregation:
According to Mendel’s Principle of Segregation, a heterozygous parent passes down a randomly selected allele for a particular trait to its offspring. The offspring receives one allele from each parent.
On observation, it is found that homozygous parents with contrasting traits produce an F1 generation expressing dominant traits and the F2 generation expresses both dominant and recessive traits in the ratio of 3:1.
3. Law of Independent Assortment:
According to Mendel’s Law of Independent Assortment, alleles for different traits are passed onto the next generation, independently of one another. Mendel found that there was a ratio of 3:1 between the dominant and recessive phenotypes for a monohybrid cross. However, a dihybrid cross resulted in a ratio of 9:3:3:1.

Note:
A Mendelian trait is a trait that is controlled by a singular locus in the inheritance pattern. Mendel’s research was ignored by the scientific community at his time. Mendel’s principles of inheritance were proposed in 1865 by Gregor Mendel.