Suppose a genotype for a protein-producing gene can have any combination of three alleles, A₁, A₂, and A₃.

Each allele produces a protein with a distinct electrophoretic mobility. Allele A₁ has the highest electrophoretic mobility, A₃ has the lowest electrophoretic mobility, and the electrophoretic mobility of A₂ is intermediate between them. Draw the appearance of gel electrophoresis protein bands for each of the possible genotypes. Be sure to label each lane of the gel with the corresponding genotype.

Verified step by step guidance

1. span>Identify all possible genotypes using the alleles A₁, A₂, and A₃. Since there are three alleles, the possible genotypes are: A₁A₁, A₁A₂, A₁A₃, A₂A₂, A₂A₃, and A₃A₃.</span
2. span>Understand the electrophoretic mobility of each allele: A₁ has the highest mobility, A₂ has intermediate mobility, and A₃ has the lowest mobility. This means that proteins produced by these alleles will migrate differently on a gel.</span
3. span>For each genotype, determine the number of bands and their relative positions on the gel. Homozygous genotypes (A₁A₁, A₂A₂, A₃A₃) will show a single band corresponding to the mobility of the allele. Heterozygous genotypes (A₁A₂, A₁A₃, A₂A₃) will show two bands, each corresponding to the mobility of one of the alleles.</span
4. span>Draw the gel electrophoresis: Create a diagram with lanes for each genotype. Label each lane with the genotype and draw bands at positions corresponding to the electrophoretic mobility of the alleles. For example, A₁A₁ will have a single band at the highest position, A₃A₃ will have a single band at the lowest position, and A₁A₂ will have two bands, one at the highest and one at the intermediate position.</span
5. span>Ensure that the gel diagram is clear and accurately represents the relative positions of the bands for each genotype. This visual representation will help in understanding how different genotypes can be distinguished based on their electrophoretic profiles.</span

Key Concepts

Alleles and Genotypes

Alleles are different versions of a gene that can produce variations in traits. In this scenario, the alleles A₁, A₂, and A₃ represent different forms of a protein-producing gene. A genotype refers to the specific combination of alleles an individual possesses, which can influence the phenotype, or observable traits, such as protein production.

Electrophoretic Mobility

Electrophoretic mobility is a measure of how quickly a protein moves through a gel when an electric current is applied. This movement is influenced by the protein's size and charge. In this case, the alleles produce proteins with distinct mobilities: A₁ moves fastest, A₂ has intermediate mobility, and A₃ moves slowest, which will be reflected in the gel electrophoresis results.

Gel Electrophoresis

Gel electrophoresis is a laboratory technique used to separate proteins based on their size and charge. In this process, a gel matrix is used to create a medium through which proteins migrate when an electric field is applied. The resulting bands on the gel correspond to different genotypes, allowing for visual identification of the alleles present in each sample based on their electrophoretic mobility.