Exploring Monohybrid Crosses and Punnett Squares

This video tutorial from Moomoomath and Science explains the basics of Punnett squares, focusing on genetic vocabulary such as traits and alleles. It covers the difference between dominant and recessive alleles and provides a step-by-step guide to setting up and solving a Punnett square. An example problem involving heterozygous flowers is used to illustrate the process, showing how to determine the probability of offspring traits.

What is a trait in genetics?

• A tool used to predict genetic outcomes

• A type of genetic disorder

• A characteristic that can be passed from one generation to another

• A specific type of dominant allele

Tags

NGSS.MS-LS4-4

What does it mean if an allele is described as recessive?

• It is always expressed if present

• It can only be expressed when paired with another recessive allele

• It is more common than dominant alleles

• It prevents the expression of other alleles

What does a heterozygous genotype typically consist of?

• Three alleles of different types

• Two recessive alleles

• Two dominant alleles

• One dominant and one recessive allele

Which combination of alleles results in a heterozygous phenotype?

• One dominant and one recessive allele

• Two recessive alleles

• Two dominant alleles

• Three recessive alleles

Which scenario describes a homozygous genotype?

• One dominant and one recessive allele

• Two different alleles

• Two recessive alleles

• One allele only

In a Punnett square, what does a capital letter represent?

• An environmental factor

• A phenotype

• A dominant trait

• A recessive trait

How is a recessive trait expressed in a genotype?

• With one capital and one lowercase letter

• With no letters

• With two capital letters

• With two lowercase letters

What is the first step in setting up a Punnett square?

• Write the genotype of the offspring

• Predict the possible outcomes

• Determine the phenotype percentages

• Draw the square

What percentage does each box in a Punnett square represent?

• 10%

• 75%

• 25%

• 50%

What is the probability of offspring being white when crossing two heterozygous red flowers?

• 50%

• 100%

• 25%

• 75%