Transcript Chapter 11

Chapter 11 Complex Inheritance and
Human Heredity
Section 1: Basic Patterns of Human Inheritance
Section 2: Complex Patterns of Inheritance
Section 3: Chromosomes and Human Heredity
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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
homozygous
recessive for
the trait.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Cystic Fibrosis
 Affects the mucus-producing glands,
digestive enzymes, and sweat glands
 Chloride ions are not absorbed into the
cells of a person with cystic fibrosis but
are excreted in the sweat.
 Without sufficient chloride ions in the cells,
a thick mucus is secreted.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Albinism
 Caused by altered genes, resulting in the
absence of the skin pigment melanin in hair
and eyes
 White hair
 Very pale skin
 Pink pupils
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Tay-Sachs Disease
 Caused by the absence of the enzymes
responsible for breaking down fatty acids
called gangliosides
 Gangliosides accumulate in the brain,
inflating brain nerve cells and causing
mental deterioration.
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Galactosemia
 Recessive genetic disorder characterized by
the inability of the body to digest galactose.
Dominant Genetic Disorders
• These diseases are caused when an
individual is homozygous dominant or
heterozygous
• In order to NOT HAVE THESE DISEASES
the normal person is homozygous recessive
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Dominant Genetic Disorders
 Huntington’s disease affects the nervous
system.
 Achondroplasia is a genetic condition that
causes small body size and limbs that are
comparatively short. (this is a type of
dwarfism)
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Chapter 11
Complex Inheritance and Human Heredity
Chapter 11
Complex Inheritance and Human Heredity
11.1 Basic Patterns of Human Inheritance
Pedigrees
 A diagram that traces the inheritance of a particular
trait through several generations of the same family
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.
Scientists can determine if a trait is dominant or
recessive
Predicting Disorders
 Record keeping helps scientists use
pedigree analysis to study inheritance
patterns, determine phenotypes, and
ascertain genotypes.
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. (it is a mix of physical appearance
between the dominant and the recessive)
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Codominance
 Both alleles are expressed in the
heterozygous condition.
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Sickle-cell Disease
Normal red blood cell
 Changes in hemoglobin
cause red blood cells to
change to a sickle shape.
 People who are
heterozygous for the trait
have both normal and
sickle-shaped cells.
Sickle cell
7766x
Sickle-cell disease and Malaria
• In Africa there is a high number of people
who have the sickle-cell allele.
• People who are heterozygous for sickle-cell
have a higher resistance to malaria.
• They go on to reproduce and pass on the
sickle-cell trait.
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Multiple Alleles
 Blood groups in
humans (this shows
both multiple alleles
and codominance)
 ABO blood groups
have three forms
of alleles.
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.
 C>cch> ch>c (this shows that one is dominant to
the next with “c” being least dominant)
 There are 10 possible genotypes and four
phenotypes for rabbit fur color
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Coat Color of Rabbits
Chinchilla
Albino
Light gray
Dark gray
Himalayan
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Epistasis
 Variety is the result of one allele hiding the
effects of another allele.
eebb
eeB_
No dark pigment present in fur
E_bb
E_B_
Dark pigment present in fur
Labrador Coat Color
• There are two sets of alleles (“E” and “B”) that
determine whether the fur will be dark or not.
• If the dog has Ee or EE it will make the fur color
dark (it is written as Eebb or EEbb)
• If the dog has ee then the fur coat will be light
(eebb, eeBb, eeBB) and produce a yellow coat
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Sex Determination
 Sex chromosomes
determine an
individual’s gender.
 Autosomes are all the
other chromosomes
that determine
everything else. (ie.
Body cells)
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. (Thus, it is larger than the
Y chromosome)
 The Y chromosome mainly has genes that
relate to the development of male
characteristics.
• Chromosome inactivation
– Coat color of the calico cat is determined by which
X chromosome is deactivated. If the X
chromosome that carries the dark coat color is
inactivated, the cat will have orange coloring. If
the X chromosome that carries the orange coat
color is inactivated, the cat will have black spots.
– Barr bodies: the inactivated X chromosome in
females
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Sex-Linked Traits
 Genes located on the X chromosome that control
traits
 Since males have only 1 X chromosome they are
affected by recessive X-linked traits
 Females are less likely to express a recessive trait
because she has two X chromosomes. One of the
X chromosomes can mask the affect of the trait.
Sex-Linked
Traits
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Sex-Linked Traits
 Red-green color blindness
This is a recessive X-linked trait. A male only
needs one copy of this allele in order to be
colorblind.
A female would need to have two copies of the
recessive allele. Thus it is very rare to find a
color blind female.
Sex-Linked
Traits
Hemophilia
• Another recessive sex-linked disorder
characterized by delayed clotting of the
blood.
• Very rare in females because she would
need to have both X chromosomes with the
recessive trait.
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. This is really how
height, eye color and fingerprints are inherited.
Chapter 11
Complex Inheritance and Human Heredity
11.2 Complex Patterns of Inheritance
Environmental Influences on phenotype
 Environmental factors
 Diet and exercise
 Sunlight and water (flowering in plants)
 Temperature (arctic fox)
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.
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.
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
 They might also be involved in aging and
cancer
Chapter 11
Complex Inheritance and Human Heredity
11.3 Chromosomes and Human Heredity
Nondisjunction
 Cell division during which sister chromatids
fail to separate properly
 If this occurs during Meiosis I or II then the
resulting gametes will not have the correct
number of chromosomes
 Down syndrome: nondisjunction occurred on
chromosome 21.
The result is short stature, heart defects,
and mental disability
Nondisjunction
• Nondisjunction occurs in both autosomes
(body cells) and in gametes
Centromere
Sister
chromatids
Pair of homologous
chromosomes
5
Chapter 11
Complex Inheritance and Human Heredity
Chapter 11
Complex Inheritance and Human Heredity
Chapter Resource Menu
Chapter Diagnostic Questions
Formative Test Questions
Chapter Assessment Questions
Standardized Test Practice
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Animation
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Chapter 11
Complex Inheritance and Human Heredity
Chapter Diagnostic
Questions
Identify the disease characterized by the
absence of melanin.
A. albinism
B. cystic fibrosis
C. galactosemia
D. Tay-Sachs
0%
A
1.
2.
3.
4.
A
B
C
D
0%
0%
B
C
0%
D
Chapter 11
Complex Inheritance and Human Heredity
Chapter Diagnostic
Questions
An individual with Tay-Sachs disease would be
identified by which symptom?
A. excessive mucus
production
B. an enlarged liver
C. a cherry-red spot on
the back of the eye
D. vision problems
0%
A
1.
2.
3.
4.
A
B
C
D
0%
0%
B
C
0%
D
Chapter 11
Complex Inheritance and Human Heredity
Chapter Diagnostic
Questions
Under what circumstances will a recessive trait
be expressed?
A. A recessive allele is
passed on by both parents.
B. One parent passes on the
recessive allele.
C. The individual is
heterozygous for the trait.
D. There is a mutation in the
dominant gene.
0%
A
1.
2.
3.
4.
A
B
C
D
0%
0%
B
C
0%
D
Chapter 11
Complex Inheritance and Human Heredity
11.1 Formative
Questions
Which of Dr. Garrod’s observations about alkaptonuria
was most critical to his determination that it is a genetic
disorder?
A. It appears at birth and
runs in families.
B. It is linked to an
enzyme deficiency.
C. It continues throughout a
patient’s life, affecting
bones and joints.
D. It is caused by acid excretion
and results in black urine.
0%
A
1.
2.
3.
4.
A
B
C
D
0%
0%
B
C
0%
D
Chapter 11
Complex Inheritance and Human Heredity
11.1 Formative
Questions
Which is the genotype of a person who is
a carrier for a recessive genetic disorder?
A. DD
B. Dd
C. dd
D. dE
0%
A
1.
2.
3.
4.
A
B
C
D
0%
0%
B
C
0%
D
Chapter 11
Complex Inheritance and Human Heredity
11.1 Formative
Questions
Albinism is a recessive condition. If an albino
squirrel is born to parents that both have normal fur
color, what can you conclude about the genotype of
the parents?
0%
0%
0%
D
A
B
C
D
C
1.
2.
3.
4.
B
0%
A
A. at least one parent is
a carrier
B. both parents are carriers
C. both parents are
homozygous recessive
D. at least one parent is
homozygous dominant
Chapter 11
Complex Inheritance and Human Heredity
11.2 Formative
Questions
When a homozygous male animal with black fur
is crossed with a homozygous female with white
fur, they have offspring with gray fur. What type
of inheritance does this represent?
0%
B
A
0%
A
B
C
D
0%
0%
D
1.
2.
3.
4.
C
A. dosage compensation
B. incomplete dominance
C. multiple alleles
D. sex-linked
Chapter 11
Complex Inheritance and Human Heredity
11.2 Formative
Questions
Of the 23 pairs of chromosomes in human
cells, one pair is the _______.
0%
B
A
0%
A
B
C
D
0%
0%
D
1.
2.
3.
4.
C
A. autosomes
B. Barr bodies
C. monosomes
D. sex chromosomes
Chapter 11
Complex Inheritance and Human Heredity
11.2 Formative
Questions
Which is an example of a polygenic trait?
0%
B
A
0%
A
B
C
D
0%
0%
D
1.
2.
3.
4.
C
A. blood type
B. color blindness
C. hemophilia
D. skin color
Chapter 11
Complex Inheritance and Human Heredity
11.3 Formative
Questions
What does a karyotype show?
A. The blood type of an
individual.
D. The phenotype of
individuals in a pedigree.
A
0%
0%
B
C. The cell’s chromosomes
arranged in order.
A
B
C
D
0%
0%
D
1.
2.
3.
4.
C
B. The locations of genes
on a chromosome.
Chapter 11
Complex Inheritance and Human Heredity
11.3 Formative
Questions
What is occurring in
this diagram?
0%
0%
D
0%
B
0%
A
B
C
D
C
1.
2.
3.
4.
A
A. multiple alleles
B. nondisjunction
C. nonsynapsis
D. trisomy
Chapter 11
Complex Inheritance and Human Heredity
11.3 Formative
Questions
What condition occurs when a person’s cells
have an extra copy of chromosome 21?
0%
0%
0%
D
A
B
C
D
C
A
0%
1.
2.
3.
4.
B
A. Down syndrome
B. Klinefelter’s syndrome
C. Tay-Sachs syndrome
D. Turner’s syndrome
Chapter 11
Complex Inheritance and Human Heredity
Chapter Assessment
Questions
Use the figure to describe what
the top horizontal line between
numbers 1 and 2 indicates.
0%
B
0%
A
B
C
D
0%
0%
D
1.
2.
3.
4.
C
1 and 2 are siblings
1 and 2 are parents
1 and 2 are offspring
1 and 2 are carriers
A
A.
B.
C.
D.
Chapter 11
Complex Inheritance and Human Heredity
Chapter Assessment
Questions
Which is not an allele
in the ABO blood group?
A. IA
B. IO
C. IB
D. i
1.
2.
3.
4.
0%
D
0%
C
0%
B
A
0%
A
B
C
D
Chapter 11
Complex Inheritance and Human Heredity
Chapter Assessment
Questions
Down Syndrome results from what
change in chromosomes?
0%
0%
0%
D
A
B
C
D
C
A
0%
1.
2.
3.
4.
B
A. one less chromosome
on pair 12
B. one extra chromosome
on pair 21
C. one less chromosome
on pair 21
D. one extra chromosome
on pair 12
Chapter 11
Complex Inheritance and Human Heredity
Standardized Test
Practice
If a genetic disorder is caused by a dominant
allele, what is the genotype of those who do
not have the disorder?
1.
2.
3.
0%
B
A
0%
A
B
C
0%
C
A. heterozygous
B. homozygous dominant
C. homozygous recessive
Chapter 11
Complex Inheritance and Human Heredity
Standardized Test
Practice
Analyze this pedigree showing
the inheritance of a dominant
genetic disorder. Which would
be the genotype of the first
generation father?
0%
0%
A
A. RR
B. Rr
C. rr
0%
C
A
B
C
B
1.
2.
3.
Chapter 11
Complex Inheritance and Human Heredity
Standardized Test
Practice
Shorthorn cattle have an allele for both red and
white hair. When a red-haired cow is crossed with a
white-haired bull, their calf has both red and white hairs
scattered over its body. What type of inheritance does
this represent?
0%
0%
D
0%
C
0%
A
B
C
D
B
codominance
dosage compensation
epistasis
sex-linked
A
A.
B.
C.
D.
1.
2.
3.
4.
Chapter 11
Complex Inheritance and Human Heredity
Standardized Test
Practice
Why are males affected by recessive
sex-linked traits more often than are females?
0%
0%
0%
D
A
B
C
D
C
A
0%
1.
2.
3.
4.
B
A. Males have only
one X chromosome.
B. Males have two
X chromosomes.
C. Males have only
one Y chromosome.
D. The traits are located
on the Y chromosomes.
Chapter 11
Complex Inheritance and Human Heredity
Standardized Test
Practice
A carrier of hemophilia and her husband, who is
unaffected by the condition, are expecting a son.
What is the probability that their son will have
hemophilia?
0%
0%
D
0%
B
A
0%
A
B
C
D
C
1.
2.
3.
4.
A. 25%
B. 50%
C. 75%
D. 100%
Chapter 11
Complex Inheritance and Human Heredity
Glencoe Biology Transparencies
Chapter 11
Complex Inheritance and Human Heredity
Image Bank
Chapter 11
Complex Inheritance and Human Heredity
Vocabulary
Section 1
carrier
pedigree
Chapter 11
Complex Inheritance and Human Heredity
Vocabulary
Section 2
incomplete
dominance
codominance
multiple alleles
epistasis
sex chromosome
autosome
sex-linked trait
polygenic trait
Chapter 11
Complex Inheritance and Human Heredity
Vocabulary
Section 3
karyotype
telomere
nondisjunction
Chapter 11
Complex Inheritance and Human Heredity
Animation
 Visualizing Nondisjunction
Chapter 11
Complex Inheritance and Human Heredity