Mendel's Dihybrid Cross and the Genetics of Pea Plants

This video tutorial explains Gregor Mendel's dihybrid cross, focusing on a classic example using pea plants. It covers the concept of a dihybrid cross, where two organisms are heterozygous for two genes, and demonstrates how to set up a Punnett square to predict offspring phenotypes. The tutorial details the dominant and recessive alleles for pea color and pod shape, and explains the expected 9:3:3:1 phenotype ratio in the offspring. The video concludes with a breakdown of the phenotypes and encourages further exploration of related genetic concepts.

What does the term 'dihybrid' refer to in a dihybrid cross?

• A cross involving two recessive alleles

• A cross involving two dominant alleles

• A cross involving two genes

• A cross involving two different species

In the context of pea color, what does the dominant allele result in?

• Green pea color

• Round pod shape

• Yellow pea color

• Pinched pod shape

What phenotype results from a homozygous recessive genotype for pea color?

• Yellow peas

• Green peas

• Pinched pods

• Round pods

What shape does the dominant allele for pod shape result in?

• Yellow pea color

• Round pod shape

• Green pea color

• Pinched pod shape

How many different gametes can a heterozygous parent produce in a dihybrid cross?

• Five

• Two

• Four

• Three

How many squares are there in a Punnett square for a dihybrid cross?

• 8

• 16

• 4

• 12

What is the phenotypic ratio for offspring with yellow peas and round pods?

• 12/16

• 1/16

• 3/16

• 9/16

What is the expected phenotypic ratio for a dihybrid cross with unlinked autosomal genes?

• 3:1

• 9:3:3:1

• 1:1

• 2:1

Which phenotype occurs in 1/16 of the offspring in a dihybrid cross?

• Green peas, round pods

• Green peas, pinched pods

• Yellow peas, pinched pods

• Yellow peas, round pods

What is the phenotypic ratio for offspring with green peas and round pods?

• 1/16

• 12/16

• 9/16

• 3/16