Chromosomal Variation
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Lilli Howard
BIOL/GEN 313
Dr. Vollbrecht
03/31/14
1. Rearrangement: __________________________________________________________
2. Aneuploidy: _____________________________________________________________
3. Polyploidy: ______________________________________________________________
4. Which four chromosome rearrangements did we talk about?
a. _________________________________________
b. _________________________________________
c. _________________________________________
d. _________________________________________
Reference Table 9.3 on page 262
5. Describe duplication as a result of unequal crossover. What could be the result?
6. Chromosomal duplications often result in abnormal phenotypes because:
a. Developmental processes depend on the relative amounts of proteins encoded by
different genes
b. Extra copies of the genes within the duplicated region do not pair in meiosis
c. The chromosome is more likely to break when it loops in meiosis
d. Extra DNA must be replicated which slows down cell division
7. What is the difference between paracentric and pericentric inversion? How are the results
different? Which causes a dicentric chromosome?
8. Describe reciprocal and non-reciprocal translocations.
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu
9. Describe the genetic basis of Down Syndrome.
10. Briefly explain why, in humans and mammals, sex-chromosome aneuploids are more
common than autosomal aneuploids.
11. Describe the difference between auto-polyploidy and allo-polyploidy.
12. A chromosome has the following segments:
A B *C D E F G
What types of chromosome mutations are required to change this chromosome into each of
the following chromosomes? (More than one chromosome mutation may be present.)
a. A B A B * C D E F G
f. A B * E D C F G
b. A B * C D E A B F G
g. C * B A D E F G
c. A B * C F E D G
h. A B * C F E D F E D G
d. A * C D E F G
i. A B * C D E F C D F E G
e. A B * C D E
13. Which types of chromosome mutations:
a. Increase the amount of genetic material in a particular chromosome?
b. Increase the amount of genetic material in all chromosomes?
c. Decrease the amount of genetic material in a particular chromosome?
d. Change the position of DNA sequences in a single chromosome without changing
the amount of genetic material?
e. Move DNA from one chromosome to a nonhomologous chromosome?
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu