Exploring Complex Patterns of Inheritance

The video revisits Mendelian genetics, exploring genotypes, phenotypes, and alleles. It delves into incomplete dominance, codominance, and the concept of multiple alleles using blood types as an example. The video further explains pleiotropy, epistasis, and polygenic inheritance, highlighting how genes can influence multiple traits or interact to affect a single phenotype. Environmental factors are also discussed as influences on phenotypes. The video concludes by emphasizing the complexity of genetic inheritance and its implications for understanding genetic disorders.

What results from the hybridization of true-breeding red and white snapdragons?

• Pink F1 generation

• Red F1 generation

• White F1 generation

• No change in color

Which example illustrates a case of incomplete dominance?

• Human skin color variation

• Pink snapdragons from red and white parents

• Yellow Labrador retrievers regardless of pigment genes

• Pea plants with only round or wrinkled seeds

What does the dominant allele code for in pea plants that affects seed shape?

• A pigment for seed color

• A growth hormone

• An enzyme converting unbranched to branched starch

• A starch blocker

What is the effect of the recessive allele in pea seed shape?

• Causes the seed to wrinkle

• Produces a round seed

• Increases seed size

• Changes the seed color

Which blood type results from the expression of both IA and IB alleles?

• Blood type AB

• Blood type A

• Blood type B

• Blood type O

What does the expression of the i allele in blood types result in?

• No carbohydrate on the red blood cell surface

• Decreased red blood cell functionality

• Increased red blood cell size

• A carbohydrate on the red blood cell surface

What is the genetic condition where a single gene affects multiple phenotypic traits?

• Pleiotropy

• Polygenic inheritance

• Epistasis

• Codominance

Which gene is epistatic in the coat color of Labrador retrievers?

• The gene for pigment deposition

• The gene for fur texture

• The gene for black or brown pigment

• The gene for fur length

What does polygenic inheritance typically result in?

• Only two possible phenotypes

• Single, discrete phenotypic options

• Traits that vary along a continuum

• Traits not influenced by genes

Which factor can influence the expression of multifactorial traits?

• Only recessive alleles

• Only genetic makeup

• Only dominant alleles

• Environmental conditions