Genotypic and Phenotypic Ratios

The video tutorial explains how to calculate and remember phenotypic and genotypic ratios for monohybrid, dihybrid, and trihybrid crosses. It begins with an introduction to these ratios, followed by detailed calculations for each type of genetic cross. The tutorial emphasizes using the monohybrid cross ratios as a foundation for understanding more complex crosses. The video concludes with a summary and encourages viewers to subscribe for more content.

What is the phenotypic ratio for a monohybrid cross?

• 2:1

• 9:3:3:1

• 3:1

• 1:2:1

How can the phenotypic ratio for a dihybrid cross be calculated?

• By dividing the ratios of two monohybrid crosses

• By subtracting the ratios of two monohybrid crosses

• By multiplying the ratios of two monohybrid crosses

• By adding the ratios of two monohybrid crosses

What is the phenotypic ratio for a dihybrid cross?

• 2:1

• 3:1

• 9:3:3:1

• 1:2:1

What is the phenotypic ratio for a trihybrid cross?

• 27:9:9:3:3:1

• 9:3:3:1

• 1:2:1

• 3:1

What is the genotypic ratio for a monohybrid cross?

• 2:1

• 1:2:1

• 9:3:3:1

• 3:1

How is the genotypic ratio for a dihybrid cross calculated?

• By dividing the ratios of two monohybrid crosses

• By subtracting the ratios of two monohybrid crosses

• By multiplying the ratios of two monohybrid crosses

• By adding the ratios of two monohybrid crosses

What is the genotypic ratio for a dihybrid cross?

• 1:2:1:2:4:2:1:2:1

• 9:3:3:1

• 1:2:1

• 3:1

What is the genotypic ratio for a trihybrid cross?

• 1:2:1:2:4:2:1:2:1

• 27:9:9:3:3:1

• 1:2:1:2:4:2:1:2:1:2:4:2:1:2:1

• 9:3:3:1

How is the genotypic ratio for a trihybrid cross calculated?

• By adding the ratios of three monohybrid crosses

• By multiplying the ratios of three monohybrid crosses

• By subtracting the ratios of three monohybrid crosses

• By dividing the ratios of three monohybrid crosses

What should you do to easily calculate phenotypic and genotypic ratios for dihybrid and trihybrid crosses?

• Remember the ratios for monohybrid crosses

• Use a calculator

• Memorize all possible ratios

• Use a genetic software