Lecture 3 More Complex Patterns of Inheritance Recessive

Recessive Disorders • Carrier: Individual that does not show symptoms but can pass the

Incomplete Dominance • Not alleles are completely dominant. • Incomplete Dominance: When the heterozygotes

Codominance • Some traits are controlled by more than two alleles. • For example:

Human Blood Type • 4 Human Blood Types: A, B, AB, O A: IAIA

Mixing Blood Types • Can only accept: – – A: A or O B:

Polygenic Inheritance • Polygenic Inheritance: Traits are controlled by multiple genes. • For example:

Importance of Environment • The environment can also affect the phenotype. • For example:

Slides: 8

Download presentation

Lecture #3 More Complex Patterns of Inheritance

Recessive Disorders • Carrier: Individual that does not show symptoms but can pass the disease to their offspring. • 2 types: Sex-linked and Autosomal

Incomplete Dominance • Not alleles are completely dominant. • Incomplete Dominance: When the heterozygotes share phenotypes of both the homozygotes. Snapdragons: Red x White flowers makes Pink

Codominance • Some traits are controlled by more than two alleles. • For example: Human Blood Type. • Dominant: A and B type blood • Recessive: O • Type A and B exhibit codominance as well.

Human Blood Type • 4 Human Blood Types: A, B, AB, O A: IAIA or IAi B: IBIB or IBi AB: IAIB O: ii

Mixing Blood Types • Can only accept: – – A: A or O B: B or O AB: A, B, AB, O O: O • Universal Acceptor? • Universal Donor? • Which blood type is an example of codominance?

Polygenic Inheritance • Polygenic Inheritance: Traits are controlled by multiple genes. • For example: Human height, skin color, hair color

Importance of Environment • The environment can also affect the phenotype. • For example: In Siamese cats, the enzyme responsible for black fur is only active at cooler temperatures found at the extremities. – Tree leaf size/shape based on age. – Siamese cat fur pattern based on temperature – Nutrition, exercise, exposure to sunlight in humans.