Leader:
Course:
Supplemental Instruction
Instructor:
Iowa State University
Date:
Ch. 17 Control of Gene Expression in Eukaryotes
Exam 4 Review
Lilli Howard
BIOL/GEN 313
Dr. Rodermel/Dr. Tuggle
12/10/14
1. Events in bacterial and eukaryotic cells may require a cascade of gene regulation, in
which _______________________________________________________________.
2. Much of gene regulation in both bacterial and eukaryotic cells is accomplished through
proteins that bind to specific sequences in DNA. These proteins are called
___________________________ and bind to DNA with _________________________.
3. Chromatin structure plays a role in (bacterial/eukaryotic) gene regulation, but not both.
4. Chromatin structure is altered by (1) __________________________, (2) ____________
___________________ (3) _____________________________.
5. ____________________________ are changes to chromatin that affect gene expression
and are passed on to other cells or future generations.
6. Coordinate regulation in eukaryotes takes place through common response elements,
present in the ____________________ and ___________________ of the genes.
7. Regulatory proteins that affect transcription exhibit two basic types of control:
____________________ inhibit transcription (negative/positive); __________________
stimulate transcription (negative/positive).
8. Transcription initiation is a relatively simple process in _________________ cells and
regulatory proteins function by blocking or stimulating the binding of
__________________ to DNA.
9. __________________ transcription requires complex machinery that includes RNA
polymerase, general transcription factors, and transcriptional activators.
10. Some eukaryotic transcriptional regulatory proteins function at a distance from the gene
by binding to _________________, causing the formation of a loop in the DNA, which
brings the _________________ and ________________ into close proximity.
11. The greater time lag between transcription and translation in ___________________ cells
compared to _____________________ cells allows mRNA _________________ and
mRNA ________________ to play larger roles in regulation.
12. Antisense RNA molecules may act as regulators of gene expression in ______________.
13. siRNAs and miRNAs are found extensively in _____________________.
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu
Ch. 2 Chromosomes and Cellular Reproduction
For the following consider a cell that is 2n = 6
1. Draw the cell cycle. Label the number of chromosomes and number of DNA molecules at
each stage.
2. Draw mitosis. Label the number of chromosomes and number of DNA molecules at each
stage.
3. Draw the meiosis I and II. Label the number of chromosomes and number of DNA
molecules at each stage.
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu
Ch. 3 Basic Principles of Heredity
Define the following:
1. Monohybrid cross
2. Dihybrid cross
3. Reciprocal cross
4. Back cross
5. Testcross
6. What are Mendel’s First and Second Laws?
7. In cucumbers, dull fruit (D) is dominant over glossy fruit (d), orange fruit (R) is dominant
over cream fruit (r), and bitter cotyledons (B) are dominant over non-bitter cotyledons
(b). The three characters are encoded by genes located on different pairs of chromosomes.
A plant homozygous for dull, orange fruit and bitter cotyledons is crossed with a plant
that has glossy, cream fruit and non-bitter cotyledons. The F1 are intercrossed to produce
the F2.
a. Give the phenotypes and their expected proportions in the F2.
b. An F1 plant is crossed with a plant that is glossy, cream fruit and non-bitter
cotyledons. Give the phenotypes and expected proportions among the progeny of
this cross.
8. PKU is a disease that results from a recessive gene. Two normal parents produce a child
with PKU.
a. What is the probability that a sperm from the father will contain the PKU allele?
b. What is the probability that an egg from the mother will contain the PKU allele?
c. What is the probability that their next child will have PKU?
d. What is the probability their next child will be heterozygous for PKU?
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu
Ch. 4 Sex Determination and Sex Linked Characteristics
1. What are the three types of sex determination? Briefly define them. Which kind do
humans utilize?
2. Fill in the following table.
3. Define the following:
a. Turner’s Syndrome
b. Klinefelter Syndrome
c. Poly-X
4. In Drosophila, yellow body is due to an X-linked gene that is recessive to the gene for
gray body.
a. A homozygous gray female is crossed with a yellow male. The F1 are intercrossed
to produce F2. Give the genotypes and phenotypes, along with the expected
proportions, of the F1 and F2 progeny.
b. A yellow female is crossed with a gray male. The F1 are intercrossed to produce the
F2. Give the genotypes and phenotypes, along with the expected proportions, of
the F1 and F2 progeny.
c. A yellow female is crossed with a gray male. The F1 females are backcrossed with
gray males. Give the genotypes and phenotypes, along with the expected proportions, of the F2 progeny.
d. If the F2 flies in part (b) mate randomly, what are the expected phenotypic
proportions of flies in the F3?
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu
Ch. 6 Pedigree Analysis
1. Autosomal recessive traits often appear in pedigrees in which there have been
consanguineous matings, because these traits
a. Tend to skip generations
b. Appear only when both parents carry a copy of the gene for the trait, which is
more likely when the parents are related.
c. Usually arise in children born to parents who are unaffected.
d. Appear equally in males and females
2. When might you see an autosomal dominant trait skip generations?
3. How can you distinguish between an autosomal recessive trait with higher penetrance in
males and an X-linked recessive trait?
4. A male affected with an X-linked dominant trait will have what proportion of offspring
affected with the trait?
5. What features of a pedigree would distinguish between a Y-linked trait and a trait that is
rare, autosomal dominant, and sex-limited to males?
6. Why are monozygotic twins identical but dizygotic twins only have half of their genes in
common on average?
7. A trait exhibits 100% concordance for both mono and dizygotic twins. What conclusion
can you draw about the role of genetic factors in determining differences in this trait?
a.
b.
c.
d.
Genetic factors are extremely important
Genetic factors are somewhat important
Genetic factors are unimportant
Both genetic and environmental factors are important
8. What assumptions underlie the use of adoption studies in genetics?
a. Adoptees have no contact with their biological parents after birth
b. The foster parents and biological parents are not related
c. The environments of biological and adopted parents are independent
d. All of the above
1060 Hixson-Lied Student Success Center  515-294-6624  sistaff@iastate.edu  http://www.si.iastate.edu