Transcript Pedigree - Turner

Chapter Complex Inheritance and Human Heredity
11 11.2 Complex Patterns of Inheritance
Incomplete Dominance
 The heterozygous phenotype is an intermediate
phenotype between the two homozygous
phenotypes.
Chapter Complex Inheritance and Human Heredity
11 11.2 Complex Patterns of Inheritance
Codominance
 Both alleles are expressed in the heterozygous
condition.
Chapter Complex Inheritance and Human Heredity
11 11.2 Complex Patterns of Inheritance
Multiple Alleles
 Blood groups in
humans
 ABO blood groups
have three forms of
alleles.
Chapter Complex Inheritance and Human Heredity
11 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.
Chapter Complex Inheritance and Human Heredity
11 11.2 Complex Patterns of Inheritance
Coat Color of Rabbits
Chinchilla
Albino
Light gray
Dark gray
Himalayan
Chapter Complex Inheritance and Human Heredity
11 11.2 Complex Patterns of Inheritance
Sex Determination
 Sex chromosomes
determine an
individual’s gender.
Chapter Complex Inheritance and Human Heredity
11 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 Complex Inheritance and Human Heredity
11 11.2 Complex Patterns of Inheritance
Polygenic Traits
 Polygenic traits arise from the interaction of
multiple pairs of genes.
Chapter Complex Inheritance and Human Heredity
11 11.2 Complex Patterns of Inheritance
Environmental Influences
 Environmental factors
 Diet and exercise
 Sunlight and water
 Temperature
Chapter Complex Inheritance and Human Heredity
11 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.
Chapter Complex Inheritance and Human Heredity
11 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 Complex Inheritance and Human Heredity
11 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.
Chapter Complex Inheritance and Human Heredity
11 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)
I
1
2
II
1
2
3
What are the Genotypes of the people shown below?
Ff
Ff
1
Ff
2
3
F?
1
F?
2
F?
ff
3
ff
1
Ff
4
ff
4
II
5
2
F f
I
6
F f
3
Ff
What Does Each One Show?
Divorce
---
Adoption
Not Married but Biological mom and dad
Divorce and Death