Guidelines

What is the phenotype and genotype of a monohybrid cross?

What is the phenotype and genotype of a monohybrid cross?

A monohybrid cross results in a phenotypic ratio of 3:1 (dominant to recessive), and a genotypic ratio of 1:2:1 (homozygous dominant to heterozygous to homozygous recessive).

What is the phenotype of monohybrid cross?

Generally, the monohybrid cross is used to determine the dominance relationship between two alleles. The cross begins with the parental generation. And the remaining quarter of the F2s will have the recessive allele’s phenotype. This predicted 3:1 phenotypic ratio assumes Mendelian inheritance.

How many phenotypes are in a monohybrid cross?

Mendel performed seven types of monohybrid crosses, each involving contrasting traits for different characteristics. Out of these crosses, all of the F1 offspring had the phenotype of one parent, and the F2 offspring had a 3:1 phenotypic ratio.

What is the phenotypic ratio of a monohybrid cross?

The phenotypic ratio, however, is 3:1. These monohybrid crosses support the laws of Mendelian genetics. Figure 2: Punnett square showing a monohybrid cross between a) a homozygous dominant and heterzygous dominant parent and b) a heterozygous dominant and homozygous recessive parent.

What does it mean to do a monohybrid cross?

A monohybrid cross is when you are only looking at the genetic outcomes for a single gene. Understand genes and genotypes. A genotype is the heritable, genetic code of an individual. An individual’s genotype comes from the alleles on the two chromosomes inherited from their parent.

Which is recessive BB in a monohybrid cross?

However, if the parent is blonde you know their genotype is the recessive bb. Count the number of each genotype. For a monohybrid cross, there are only three possible genotypes: BB, Bb, and bb. BB (brown hair) and bb (blonde hair) are homozygous for a gene meaning that they have two identical alleles for one gene.

What are the phenotypes of a BB X BB cross?

In the BB x Bb cross, the phenotypes will be four dominant brown-haired offspring (2 BB and 2 Bb) to zero recessive blonde-haired offspring (bb) so the ratio would be 4:0. 100% of the offspring will have brown hair, but 50% of them will be homozygous while the other 50% will be heterozygous.