Incomplete Dominance, Codominance, Polygenic Traits, and Epistasis!

The video explores non-Mendelian genetic traits, including incomplete dominance, codominance, polygenic traits, and epistasis. It uses examples like snapdragons, speckled chickens, and llamas to illustrate these concepts. The video emphasizes the importance of understanding these genetic variations and advises caution when identifying non-Mendelian traits in problem-solving.

What is a key characteristic of non-Mendelian traits?

• They involve only one gene.

• They do not follow the regular Mendelian rules.

• They are only found in plants.

• They always follow Mendel's laws.

In incomplete dominance, what is the result of crossing a red and a white snapdragon?

• All offspring are pink.

• All offspring are white.

• All offspring are red.

• Offspring are either red or white.

How does codominance differ from incomplete dominance?

• In codominance, only recessive alleles are expressed.

• In codominance, one allele is completely dominant.

• In codominance, both alleles are expressed together.

• In codominance, neither allele is expressed.

What is a polygenic trait?

• A trait controlled by a single gene.

• A trait influenced by multiple genes.

• A trait that is not influenced by genes.

• A trait that is only found in animals.

Which of the following can influence polygenic traits like height?

• Neither genetic nor environmental factors.

• Both genetic and environmental factors.

• Only genetic factors.

• Only environmental factors.

What is epistasis?

• A gene that is never expressed.

• A gene that is always expressed.

• One gene depending on another gene for expression.

• A single gene controlling multiple traits.

In the example of llamas, what happens if a llama has the genotype cc?

• The llama will have brown wool.

• The llama will be albino.

• The llama will have no wool.

• The llama will have black wool.