Transcript Dominant & Recessive Genetic Disorder Notes (11.1)

Dominant & Recessive Genetic Disorders (11.1)
State Standard
2C. Using Mendel’s laws, explain the role of
meiosis in reproductive variability.
2D. Describe the relationships between changes
in DNA and potential appearance of new traits
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Recessive Genetic Disorders
 A recessive trait
is expressed
when the
individual is
____________
recessive for the
____________.
 A person who is
heterozygous is
called a
____________.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Cystic Fibrosis (Recessive)
 Common among ____________
 Affects the ____________ -producing glands,
digestive ____________, and sweat glands
 Chloride ____________ are not absorbed
into the cells of a person with cystic fibrosis
but are ____________ in the sweat.
 Without sufficient chloride ions in the cells, a
thick ____________ is secreted.
 Treatment includes physical therapy,
medication, & special diets.
A normal woman marries a man with cystic fibrosis. If they
have children, what ratio will be totally normal? Explain.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Albinism (Recessive)
 Caused by altered ____________, resulting
in the absence of the skin pigment
____________ in ____________, skin, and
____________
 ____________ e hair
 Very pale ____________
 ____________ pupils
 Sun’s ____________ radiation is
especially dangerous
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Albinism (Recessive)
An albino man marries a woman who is a carrier. Create a
Punnett Square to show the possibilities of their offspring.
Include genotypic & phenotypic ratios.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Tay-Sachs Disease (Recessive)
 Recessive disorder on chromosome _______
 Caused by the absence of the ____________
responsible for breaking down ____________
____________ called gangliosides
 Gangliosides accumulate in the
____________, inflating brain nerve cells
and causing mental ____________.
 Occurs predominantly in ____________ of
Eastern European descent.
A man & woman who are both Tay Sachs carriers get
married & decide to have children. What percent chance is
there of them having a purebred normal baby? Use a
Punnett Square to determine your answer.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Galactosemia (Recessive)
 Recessive genetic disorder characterized by
the inability of the body to digest
____________.
 These people must avoid ____________
products.
 Milk products will cause numerous
complications, including ____________
disability.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Dominant Genetic Disorders
 Because these disorders are caused by a
____________ allele, they affect people who
are homozygous dominant and people who
are ____________.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Huntington’s Disease (Dominant)
 Huntington’s disease affects the
____________ system.
 Occurs in 1 in ____________ humans.
 Symptoms first appear between the ages of
____________.
 Symptoms include loss of ____________
function, uncontrollable ____________, and
emotional disturbances.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Huntington’s Disease (Dominant)
A woman who is hybrid for Huntington’s marries a man
who is normal. What will be the genotypic & phenotypic
ratios of their children?
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Achondroplasia (Dominant)
 Achondroplasia is a genetic condition that
causes ____________ body size and limbs
that are comparatively ____________.
 Most common form of ____________.
 Adult height of about ____________ feet.
 Normal life expectancy.
A man & woman who are both heterozygous for
Achondroplasia have children. Can they have a normal
child? Explain
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
____________
 A diagram that traces the ____________ of a
particular ____________ through several
generations
Label each part of the diagram below
Pedigree Challenge
On your first day interning in the office of a human
geneticist, a man with purple ears walks in. You
questioned the man and wrote down the following
family history.
The man's mother and one of his sisters also had
purple ears, but his father, his brother, and two other
sisters had normal ears. The man and his normaleared wife had seven children, including four boys
and three girls. Two girls and two boys had purple
ears.
Draw the family pedigree and indicate what form of
inheritance that the purple-ear trait most likely follows.
(Is it dominant or a recessive passed trait?)
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Inferring Genotypes
 Knowing physical traits can determine what
____________ an individual is most likely to
have.
Predicting Disorders
 Record keeping helps scientists use
pedigree analysis to study inheritance
patterns, determine ____________, and
ascertain ____________.