Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Incomplete Dominance The heterozygous phenotype is an intermediate phenotype between the two homozygous phenotypes.

Both alleles are expressed in the heterozygous condition. Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Codominance Both alleles are expressed in the heterozygous condition.

ABO blood groups have three forms of alleles. Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Multiple Alleles Blood groups in humans ABO blood groups have three forms of alleles.

Multiple alleles can demonstrate a hierarchy of dominance. Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Coat Color of Rabbits Multiple alleles can demonstrate a hierarchy of dominance. In rabbits, four alleles code for coat color: C, cch, ch, and c. Option 2 (continued on the next slide)

Coat Color of Rabbits 11.2 Complex Patterns of Inheritance Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Coat Color of Rabbits Chinchilla Albino Light gray Option 2 Dark gray Himalayan

Sex chromosomes determine an individual’s gender. Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Sex Determination Sex chromosomes determine an individual’s gender.

Chromosome inactivation Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Dosage Compensation The X chromosome carries a variety of genes that are necessary for the development of both females and males. The Y chromosome mainly has genes that relate to the development of male characteristics. Chromosome inactivation Barr bodies

Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Polygenic Traits Polygenic traits arise from the interaction of multiple pairs of genes.

Environmental Influences Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Environmental Influences Environmental factors Diet and exercise Sunlight and water Temperature

Chapter 11 Complex Inheritance and Human Heredity 11.2 Complex Patterns of Inheritance Twin Studies Helps scientists separate genetic contributions from environmental contributions Traits that appear frequently in identical twins are at least partially controlled by heredity. Traits expressed differently in identical twins are strongly influenced by environment.

Telomere caps consist of DNA associated with proteins. Chapter 11 Complex Inheritance and Human Heredity 11.3 Chromosomes and Human Heredity Telomeres Telomere caps consist of DNA associated with proteins. Serves a protective function for the structure of the chromosome

Chapter 11 Complex Inheritance and Human Heredity 11.1 Basic Patterns of Human Inheritance Inferring Genotypes Knowing physical traits can determine what genes an individual is most likely to have. Predicting Disorders Record keeping helps scientists use pedigree analysis to study inheritance patterns, determine phenotypes, and ascertain genotypes.

Images of chromosomes stained during metaphase Chapter 11 Complex Inheritance and Human Heredity 11.3 Chromosomes and Human Heredity Karyotype Studies Karyotype—micrograph in which the pairs of homologous chromosomes are arranged in decreasing size. Images of chromosomes stained during metaphase Chromosomes are arranged in decreasing size to produce a micrograph.

Pedigree = Males Key: = Females Shading = Have trait (Attached Earlobes = f ) No Shading = Do not have trait (Free Earlobes = F) 1 2 3 I II

What are the Genotypes of the people shown below? 4 5 1 2 3 6 I II F ff f f f ? ? ? f f f f

Not Married but Biological mom and dad What Does Each One Show? - - - - - - Divorce - - - Adoption Not Married but Biological mom and dad Divorce and Death