Suppose you have monohybrid snapdragons in your garden and you find that they produce red seeds to white seeds in the ratio of 3:1. If the alleles are designated R (red seeds) and r (white seeds), what are the probable phenotypes of the parents (P1)?
a all white
b all red
c half red and half white
d unable to determine
In order to determine the probable phenotypes of the parents, we can analyze the given ratio of red to white seeds produced by the monohybrid snapdragons.
The ratio of 3:1 suggests that there is a dominant allele (R) and a recessive allele (r) at play in this monohybrid cross. According to Mendel's laws of inheritance, if a trait is controlled by a single gene, and one allele is dominant over the other, then the dominant trait will be expressed in the phenotype.
Since red seeds are expressed in a 3:1 ratio compared to white seeds, it can be inferred that red seeds are the dominant trait and white seeds are the recessive trait. Therefore, the probable phenotypes of the parents can be deduced based on this information.
Given that the ratio of red (R) to white (r) seeds is 3:1, the most likely phenotypes of the parents (P1) are:
c) half red and half white
This suggests that one parent plant in the cross may be heterozygous (Rr), possessing one dominant allele (R) and one recessive allele (r), while the other parent may be homozygous recessive (rr), carrying two recessive alleles.
However, it is important to note that without further information or observations, it is impossible to definitively determine the phenotypes of the parents.