Question

A pea plant with purple flowers was crossed with white flowers, producing 50 plants with only purple flowers. On selfing, these plants produced 482 plants with purple flowers and 162 with white flowers. What genetic mechanism accounts for these results? Explain.

Answer 1

Hint: Mendel's law of dominance states that in a heterozygote one trait will conceal the presence of another trait for the same characteristic. Rather than both alleles contributing to a phenotype, the dominant allele will be expressed exclusively.

Step by step answer:In this cross, purple colour dominates over white colour flowers so F1 generation contains all the purple flowers.
 

Law of segregation - According to the law of segregation, only one of the two gene copies present in an organism is distributed to each gamete (egg or sperm cell) that it makes, and the allocation of the gene copies is random. In F2 generation at the time of gamete formation genes segregate on different chromosomes and the segregation is random. It is not clear which gene will be passed on to the zygote so both white and purple colour over are formed.

Note: In the year 1860, Gregor Johann Mendel, the father and founder of genetics unlocked the mystery of genetics. He conducted many experiments on the pea plants and observed their pattern of inheritance from one generation to the next generation. His investigation led to the discovery of three laws of inheritance, famously known as Mendel’s Laws of Inheritance.