Polygenic Traits and Alleles

The video discusses two Mendelian exceptions: multiple alleles and polygenic traits. Multiple alleles involve more than two allele options, but only two are inherited, exemplified by blood type. Polygenic traits, like eye color, involve many genes, leading to a wide variety of phenotypes. The video explains the complexity of these genetic concepts and why Punnett squares are not always applicable.

What is an example of a trait determined by multiple alleles?

• Eye color

• Blood type

• Height

• Hair color

How many alleles do you inherit for a trait controlled by multiple alleles?

• Three

• Four

• One

• Two

Why are Punnett squares more complex with multiple alleles?

• Because they require a larger grid

• Because they involve environmental factors

• Because there are more than two allele options

• Because they involve more than one gene

What does the term 'polygenic' mean?

• Controlled by one gene

• Controlled by many genes

• Controlled by environmental factors

• Controlled by a single allele

Which of the following is an example of a polygenic trait?

• Widow's peak

• Hitchhiker's thumb

• Eye color

• Blood type

Why is it difficult to use Punnett squares for polygenic traits?

• Because they involve many genes and phenotypes

• Because they have a fixed number of phenotypes

• Because they involve only one gene

• Because they are influenced by nutrition

What is a characteristic of polygenic traits?

• They have a limited number of phenotypes

• They are controlled by a single gene

• They show a wide variety of phenotypes

• They are not influenced by environmental factors

Which of the following is NOT typically controlled by multiple genes?

• Eye color

• Height

• Blood type

• Hair color

What is a common misconception about human eye color?

• It is controlled by a single gene

• It is determined by environmental factors

• It has only two options: blue and brown

• It is not influenced by genetics

What is a challenge in studying polygenic traits?

• They have a fixed number of alleles

• They are not influenced by genes

• They are easy to predict

• They involve complex genetic interactions