1. Chromosomal Abnormalities (11.3)
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

2. 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.
Used to identify chromosome abnormalities

3. Normal Karyotype

4. Cell division during which sister chromatids fail to separate properly
Chapter 11
Complex Inheritance and Human Heredity
11.3 Chromosomes and Human Heredity
Nondisjunction
Cell division during which sister chromatids fail to separate properly
Nondisjunction on autosomes (non-sex chromosomes – 1-22) can cause:
Down Syndrome (Trisomy 21)
Patau Syndrome (Trisomy 13)
Edwards Syndrome (Trisomy 18)

5. Nondisjunction Cont’d
Chapter 11
Complex Inheritance and Human Heredity
11.3 Chromosomes and Human Heredity
Nondisjunction Cont’d
Nondisjunction on sex chromosomes can cause…
Turner Syndrome (female w/ only 1 X chromosome
Klinefelter’s Syndrome (male w/ an extra X chromosome

6. Nondisjunction

7. Chapter 11
Complex Inheritance and Human Heredity

8. Identify the disease characterized by the absence of melanin.
Chapter 11
Complex Inheritance and Human Heredity
Chapter Diagnostic Questions
Identify the disease characterized by the
absence of melanin.
albinism
cystic fibrosis
galactosemia
Tay-Sachs A B C D
CDQ 1

9. An individual with Tay-Sachs disease would be
Chapter 11
Complex Inheritance and Human Heredity
Chapter Diagnostic Questions
An individual with Tay-Sachs disease would be
identified by which symptom?
excessive mucus production
an enlarged liver
a cherry-red spot on the back of the eye
vision problems A B C D
CDQ 2

10. Under what circumstances will a recessive trait be expressed?
Chapter 11
Complex Inheritance and Human Heredity
Chapter Diagnostic Questions
Under what circumstances will a recessive trait
be expressed?
A recessive allele is passed on by both parents.
One parent passes on the recessive allele.
The individual is heterozygous for the trait.
There is a mutation in the dominant gene. A B C D
CDQ 3

11. Which is the genotype of a person who is
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? DD Dd dd dE A B C D
FQ 2

12. 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?
at least one parent is a carrier
both parents are carriers
both parents are homozygous recessive
at least one parent is homozygous dominant A B C D
FQ 3

13. 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?
dosage compensation
incomplete dominance
multiple alleles
sex-linked A B C D
FQ 4

14. Of the 23 pairs of chromosomes in human
Chapter 11
Complex Inheritance and Human Heredity
11.2 Formative Questions
Of the 23 pairs of chromosomes in human
cells, one pair is the _______.
autosomes
Barr bodies
monosomes
sex chromosomes A B C D
FQ 5

15. What does a karyotype show?
Chapter 11
Complex Inheritance and Human Heredity
11.3 Formative Questions
What does a karyotype show?
The blood type of an individual.
The locations of genes on a chromosome.
The cell’s chromosomes arranged in order.
The phenotype of individuals in a pedigree. A B C D
FQ 7

16. What is occurring in this diagram?
Chapter 11
Complex Inheritance and Human Heredity
11.3 Formative Questions
What is occurring in this diagram?
multiple alleles
nondisjunction
nonsynapsis
trisomy A B C D
FQ 8

17. What condition occurs when a person’s cells
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?
Down syndrome
Klinefelter’s syndrome
Tay-Sachs syndrome
Turner’s syndrome A B C D
FQ 9

18. 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.
1 and 2 are siblings
1 and 2 are parents
1 and 2 are offspring
1 and 2 are carriers A B C D
CAQ 1

19. Which is not an allele in the ABO blood group? IA IO IB i
Chapter 11
Complex Inheritance and Human Heredity
Chapter Assessment Questions
Which is not an allele
in the ABO blood group? IA IO IB i A B C D
CAQ 2

20. Down Syndrome results from what change in chromosomes?
Chapter 11
Complex Inheritance and Human Heredity
Chapter Assessment Questions
Down Syndrome results from what change in chromosomes?
one less chromosome on pair 12
one extra chromosome on pair 21
one less chromosome on pair 21
one extra chromosome on pair 12 A B C D
CAQ 3

21. If a genetic disorder is caused by a dominant
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?
heterozygous
homozygous dominant
homozygous recessive A B C
STP 1

22. RR Rr rr Standardized Test Practice
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? A B C RR Rr rr
STP 2

23. Standardized Test Practice
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? A B C D
codominance
dosage compensation
epistasis
sex-linked
STP 3

24. Males have only one X chromosome. Males have two X chromosomes.
Chapter 11
Complex Inheritance and Human Heredity
Standardized Test Practice
Why are males affected by recessive sex-linked traits more often than are females?
Males have only one X chromosome.
Males have two X chromosomes.
Males have only one Y chromosome.
The traits are located on the Y chromosomes. A B C D
STP 4

25. 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?
25%
50%
75%
100% A B C D
STP 5