Question

Explain independent inheritance of two separate traits, i.e., shape and colour of seed (Round -Green RRyy and Wrinkled - yellow rrYY) Draw flow chart for $F1$ and self-pollinated $F2$ generation. Write the ratio.

Answer 1

In the field of genetics, Mendel laid the foundations and ultimately formulated the laws of inheritance. Gregor Mendel suggested three laws of inheritance: The Law of Segregation, the Law of Independent Assortment, and the Law of Dominance. His studies on pea plants with a range of traits resulted in these rules. Mendel used monohybrid crosses to investigate the inheritance of one gene in plants.

Complete answer:
True-breeding lines of wrinkled yellow peas (rrYY) and round green peas form the P (Parental) cross (RRyy). As a result, all are RrYy alleles, these show round and yellow seeds. The alleles at the two loci segregate independently in the formation of $F2$ plants. That is, the odds of having a R and a Y allele are $\dfrac{1}{2} \times \dfrac{1}{2}$, a R and a y are $\dfrac{1}{2} \times \dfrac{1}{2}$, and so on. As a result, all four potential diallelic combinations have a $\dfrac{1}{4}$ chance of occurring. Both parents are in the same boat. There are $4 \times 4 = 16$ possible $F2$ combinations given four possible gamete types in each parent, and the likelihood of any particular dihybrid form is $\dfrac{1}{4} \times \dfrac{1}{4} = \dfrac{1}{{16}}$.
That is, we expect round-yellow: wrinkled-yellow: round-green: wrinkled-green pea seeds to have a $9:3:3:1$ phenotypic ratio.

Note:
A breeding experiment between two species that are similar hybrids for two traits is known as a dihybrid cross. A dihybrid cross, to put it another way, is a cross between two species that are heterozygous for two different traits. This type of trait has individuals that are homozygous for a particular trait. Genes, which are DNA segments, decide these characteristics.
In a dihybrid cross, each phenotype is represented by a separate pair of alleles carried by the parents. The dominant allele is carried by one parent, while the recessive allele is carried by the other. The $F1$ generation's offspring are all heterozygous for particular traits as a result of the crosses.