Punnett Square Practice Problems Explained

This video tutorial by Travis Monk is part of a series on genetics, focusing on Punnett squares. It covers two example problems: a simple cross between two heterozygous parents and a more complex cross involving a homozygous recessive and a heterozygous parent. The video explains how to set up and fill out Punnett squares, interpret results, and answer related probability questions. It concludes with encouragement to practice and explore further topics in genetics.

What is the first step in solving a genetics probability question?

• Determine the phenotype of the parents

• Set up and fill out a Punnett square

• Identify the dominant and recessive traits

• Count the number of offspring

Tags

NGSS.HS-LS3-3

In a cross between two parents with genotype Bb, what is the probability of an offspring having the genotype bb?

• 0%

• 25%

• 75%

• 50%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

What percentage of the offspring would show the dominant phenotype in the first example problem?

• 25%

• 75%

• 50%

• 100%

What does it mean for an individual to be a carrier of a trait?

• They show the dominant trait

• They have two dominant alleles

• They show the recessive trait

• They do not show the trait but can pass it on

Tags

NGSS.HS-LS3-2

NGSS.HS-LS4-3

In the second example problem, what is the genotype of the homozygous recessive parent?

• BB

• bb

• bB

• Bb

Tags

NGSS.HS-LS3-2

If an individual has a dominant phenotype but a mother with a recessive genotype, what is their genotype?

• BB

• Bb

• bb

• bB

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

What percentage of the offspring in the second example would have the recessive phenotype?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

What percentage of the offspring in the second example would be heterozygous?

• 100%

• 50%

• 25%

• 75%

Tags

NGSS.HS-LS3-3

Why is it important to properly set up and fill out Punnett squares?

• To ensure accurate results

• To make the process faster

• To avoid using a calculator

• To impress the teacher

What is the purpose of creating a second Punnett square for the mother in the second example problem?

• To help understand the genotype of the second parent

• To determine the phenotype of the mother

• To verify the genotype of the offspring

• To calculate the probability of different traits

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3