What is the phenotype of YY?
What is the phenotype of YY?
Yy is the heterozygous genotype (one dominant allele, one recessive allele). The phenotype of this genotype is yellow seed color.
How many phenotypes are possible with 2 alleles?
With two loci and two alleles in a strictly additive model (i.e., no epistasis or other modifying effects) we can have five phenotypic classes aabb
What are 2 alleles of the same gene?
If the two alleles are the same, the individual is homozygous for that gene. If the alleles are different, the individual is heterozygous. Though the term allele was originally used to describe variation among genes, it now also refers to variation among non-coding DNA sequences.
What is the phenotypic ratio for the offspring of 2 heterozygous AA parents?
This 9:3:3:1 phenotypic ratio is the classic Mendelian ratio for a dihybrid cross in which the alleles of two different genes assort independently into gametes.
How is it possible for two alleles to produce three phenotypes?
Having more than 1 or 2 alleles for a trait can greatly increase the number of phenotypes, depending on the trait’s specific pattern of inheritance. For example, human blood type is controlled by 3 alleles (just referring to the ABO blood groups here): A, B, and O.
Why is the Punnett square 4×4 used in genetics?
The 4X4 square is necessary since each of the parents can produce four types of gametes, based on the distribution of the alleles of the two genes. When more than two traits are being observed, a Punnett square becomes unwieldy and other tools are used to predict the outcomes of such crosses.
Why is it called the Punnett model?
It is named after Reginald C. Punnett, who devised the approach to determine the probability of an offspring’s having a particular genotype (combination of alleles). Dominance in genetics is a relationship between alleles of a gene, in which one allele masks the expression (phenotype) of another allele.
What are the rules for creating a Punnett square?
You just need to remember that not all the genes can be used to create a Punnett square. Here’s a shortlist of rules to follow: Given traits must be inherited independently (their genes can not be located close to each other in the genetic material); A given trait must be defined only by the alleles we’re going to use in the genetic square.
How do you find the recessive allele of a Punnett square?
In every Punnett square, an allele is represented by the first letter of the dominant phenotype. In this case, the dominant yellow color allele is denoted by the capital letter ‘Y’ and the recessive allele by the small letter ‘y’.
