Punnett Square Example - Dihybrid Cross

The video tutorial explains how to construct and analyze a Punnett square for a dihybrid cross, using Guinea pigs as an example. It covers the setup of the cross, determining allele combinations using the FOIL method, and filling the Punnett square. The tutorial also discusses the genotypic and phenotypic ratios of the F1 and F2 generations, highlighting Mendel's law of independent assortment.

What is the primary purpose of a Punnett square in genetics?

• To determine the physical appearance of an organism

• To identify the dominant trait in a species

• To illustrate possible offspring combinations from a genetic cross

• To calculate the exact number of offspring

In the example of the Guinea pigs, what genotype represents the male with dominant traits?

• BbSs

• BBss

• BBSS

• bbss

Which method is used to determine possible allele combinations in a dihybrid cross?

• Cross-multiplication

• FOIL method

• Subtraction method

• Addition method

What is the genotypic ratio of the F1 generation in the given example?

• 9 BbSs to 3 bbss

• 16 BBSS to 0

• 16 BbSs to 0

• 9 BBSS to 3 BbSs

What is the famous phenotypic ratio observed in the F2 generation of a dihybrid cross?

• 3:1

• 9:3:3:1

• 1:2:1

• 4:4:4:4

Which law of genetics is demonstrated by the consistent 9:3:3:1 ratio in dihybrid crosses?

• Law of Independent Assortment

• Law of Dominance

• Law of Segregation

• Law of Recessiveness

In the F2 generation, how many offspring are expected to have the cream long phenotype?

• 1

• 9

• 16

• 3