Download Practice Exam 3 - Iowa State University

Practice Exam 3
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Stephanie
Bio 212
Howell & Sakaguchi
Nov 10-13, 2013
Study before taking this practice test. After taking it, go through the answers one by one. For the
questions you missed, circle them in red and read about the concept in the book and lecture notes. Write
a paragraph about it in your own words or draw it out in your notebook. Don’t move on until you are
sure you understand the concept. Once you fully understand, you won’t miss that type of question again!
Answers will be provided at all SI sessions from Nov 10 to 13th (Sun, Mon, and Wed). Feel free to bring
your questions to these sessions. For even more practice questions check out the exam archive on
blackboard.
Lastly, sorry about the erratic formatting. I am good at biology but dreadful at Microsoft Word.
1.
In the media in which the bacteria, E. coli, is growing, the presence of lactose .........
1) activates the CAP activator.
2) increases the binding of lac repressor to the operator of the lac operon.
3) leads to increased production of beta-galactosidase.
4) All of the above
5) None of the above
2.
The promoter regulatory elements to which activators, a class of eukaryotic transcription factors, bind are called:
1) Mediators
2) Accelerators
3) Enhancers
4) Augmentors
5) None of the above
3.
Your textbook defines three categories of cell surface receptors that respond to extracellular signals. They are:
1) Ligand-gated ion channels, steroid receptors, G-protein coupled receptors
2) Enzyme-linked receptors, G-protein coupled receptors, ligand-gated ion channels
3) Steroid receptors, enzyme-linked receptors, G-protein couple receptors
4) Ligand-gated channels, exocrine receptors, G-protein couple receptors
5) Exocrine receptors, enzyme-linked receptors, ligand-gated ion channel
4.
What is the difference between glucocorticoid and estrogen signaling?
1) Estrogens are steroid hormones and glucocorticoids are peptide hormones.
2) Estrogens are made in the ovaries, and glucocorticoids in the adrenal gland.
3) Glucocorticoids are short distance signaling hormones and estrogens are long- distance signaling hormones.
4) Glucocorticoid receptors are located in the nucleus, and estrogen receptors are located in the cytoplasm
5) All of the above
6) None of the above
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5.
Communication between the hypothalamus and the anterior pituitary gland is essential in controlling the levels of various
hormones in the bloodstream.
1) The critical connections between the hypothalamus and anterior pituitary gland that control luteinizing and follicle
stimulating hormone in the blood are neuronal (nerve) connections.
2) The anterior pituitary gland senses hormone levels in the bloodstream and signals the hypothalamus to release
luteinizing and follicle stimulating hormone
3) The critical connections between the hypothalamus and anterior pituitary gland that control luteinizing and follicle
stimulating hormone in the blood are portal vein connections.
4) Through neuronal (nerve) connections, the target tissue signals the hypothalamus and the anterior pituitary gland to
release luteinizing and follicle stimulating hormone into the bloodstream
5) All of the above
6) None of the above
6.
With reference to the above diagram from your textbook. Epinephrine acts ....
1) by transducing the hormone signal across the plasma membrane.
2) by promoting the dissociation of the G-protein
3) by promoting the exchange of GTP for GDP in the G protein
4) All of the above.
5) None of the above.
7.
Of the chemical classes of animal hormones .....
1) the steroids hormones are generally derived from brassinosteroids.
2) the amine hormones are generally derived from cholesterol.
3) the amine hormones, dopamine and epinephrine, are generally derived from the amino acid, tyrosine
4) All of the above
5) None of the above
8.
Type 1 diabetes mellitus differs from type 2 in that in .....
1) type 2 diabetes, the pancreas functions normally, but the cells in the body fail to respond normally to insulin.
2) type 2 diabetes the body’s immune system attacks and destroys the insulin producing cells in the pancreas.
3) type 1 diabetes, low levels of glucose in the bloodstream are treated by the administration of insulin.
4) None of the above.
9.
In response to unidirectional light ........
1) a plant seedling will bend away from the light.
2) the hormone auxin will accumulate on the side of the plant seedling facing the light.
3) the side of a plant seedling facing the light will grow more slowly than the side away from the light.
4) the hormone auxin will slow growth on the side of the seedling to which the hormone accumulates.
5) All of the above.
10.
Examples of plant hormones are:
1) Abscisic acid, Cytokinins and Glucocorticoids
2) Ethylene, Epidermal growth factor, Brassinosteroids
3) Abscisic acid, Cytokinins and Brassinosteroids
4) Ethylene, Insulin and Abscisic acid
11.
Gibberellins are hormones that regulate growth in flowering plants because:
1) In the presence of gibberellins, DELLA proteins are degraded.
2) In the presence of gibberellins, DELLA proteins bind to and activate the promoters of gibberellin-responsive genes.
3) In the absence of gibberellins, GID1, a factor that binds DELLA proteins is degraded.
4) All of the above.
12.
Which of the following statements is TRUE of restriction enzymes?
A. They cleave DNA only at sites with adjacent thymine bases.
B. They are not naturally produced by bacteria, but are bioengineered by them.
C. They protect bacterial cells from invasion by foreign DNA.
D. There are less than 10 restriction enzymes known.
E. None of the above.
13.
In gene cloning ....
A. A gene of interest is inserted into a recombinant vector.
B. Each bacterial colony contains many copies of a single gene of interest.
C. Most recombinant vectors are derived from plasmids.
D. A gene of interest with its sticky ends is ligated to a vector with complementary sticky ends.
E. All of the above.
14.
In polymerase chain reactions (PCR), the reaction is progressively heated and cooled. Why is that done?
A. To activate the Taq polymerase at high temperature.
B. To denature DNA strands and allow for annealing of primers.
C. To inactivate the restriction enzyme.
D. To allow for the addition of primers during the cooling period. E. All of the above
15.
A transgenic animal ......
A. cannot transmit the transgene to its progeny.
B. can be made by injecting DNA into its bloodstream.
C. was likely generated using a disabled pathogenic bacterium.
D. can express a foreign gene of interest under the control of an animal promoter. E. None of the above
16.
Compare transcription and mRNA processing in prokaryotes and eukaryotes. Which of the following aspects of
transcription is DIFFERENT in prokaryotes and eukaryotes?
a.The orientation of the template DNA strand is different.
b.The direction of synthesis of the new RNA strand is different.
c.The NTP monomers used by prokaryotes and eukaryotes are different.
d.Eukaryotes need to unwind the DNA template strand, but prokaryotes do not.
e.Eukaryotes process mRNAs after transcription in ways that prokaryotes do not.
17.
You treat a strain of bacteria with a chemical mutagen. The mutagen causes a frameshift mutation in the third codon of a
gene encoding 30 amino acids. Which of the following best describes the consequences of this frameshift mutation?
a. The frameshift mutation will interfere with DNA replication
b. The frameshift mutation will change the mRNA sequence for the sequence following the mutation.
c. The frameshift mutation will change the start codon.
d. The frameshift mutation will change the amino acid sequence encoded by this gene, starting with amino acid #3 in the
polypeptide chain.
e. The frameshift mutation will cause the ribosome to skip the mutated codon.
18.
Transcription factors regulate transcription by
1. unwinding the DNA so that it can be transcribed.
2. “charging” the tRNAs with the correct amino acids to be used in translation.
3. binding to nearby DNA sequences and regulating the recruitment of RNA polymerase.
4. producing the 5’ cap during mRNA processing.
5. splicing out non-coding introns.
19.
The trp operon includes 5 genes (trpA, trpB, trpC, trpD, trpE) that are required for tryptophan synthesis in E. coli.
Transcription of the trp operon is regulated by a repressor. The repressor is functional when it is bound to tryptophan.
How does adding tryptophan change the expression levels of trpA, trpB, trpC, trpD, and trpE? D=75
a. Adding tryptophan allows the polymerase to bind the promoter and allows the trp genes to be transcribed, increasing
expression levels.
b. Adding tryptophan activates the repressor so that the genes can only be transcribed individually and not as a single
message
c. Adding tryptophan activates the repressor so that none of the trp genes can be transcribed.
d. Adding tryptophan will have no effect on the expression levels of trp genes.
e. Adding tryptophan activates the operator so that the trp genes can be transcribed, and expression levels increase.
20.
Frequently, very few molecules of a hormone are required to affect changes in a target cell. This is because
a. hormones are lipid-soluble and readily penetrate the membranes of the target cell.
b. hormones are large molecules that remain in circulation for months and can repeatedly stimulate the same cell.
c. the mechanism of hormonal action involves an enzyme cascade that amplifies the response to a hormone.
d. the mechanism of hormonal action involves memory cells that have had prior contact with the hormone.
21.
Consider the following signal transduction event:
The first cell secretes a ligand.
The second cell (target cell) expresses a receptor that binds to the ligand.
Receptor binding results in a cascade of post-translational modifications in the cytoplasm of the second cell. What is the
consequence of a mutation that prevents expression of the receptor?
a. The cascade of post-translational modifications in the second cell will start, but will not finish.
b. The ligand will be tethered to the first cell.
c. The second cell will not be able to detect or respond to the ligand.
d. The ligand will not be secreted.
e. The second cell will not be able to respond to any environmental changes.
22.
Somatic nuclear transfer (also called cloning) is an experimental technique in which the nucleus of an egg is replaced
with the nucleus from a somatic cell. If a new organism can arise from the nucleus of a skin cell, then what causes the
form of a skin cell to be so different from that of the newly fertilized egg that it came from?
a. As it develops, the skin cell deletes DNA that is not necessary for skin cell fate
b. The skin cells has the same nuclear genome as the once-cell embryo, but it only expresses a subset of the RNAs and
proteins encoded by the genome
c. Skin cells are diploid: they have an active skin cell genome and an inactive embryonic genome
d. Skin cells don’t use genetic information in the nucleus. Their proteins are self- replicating
e. Skin cells amplify the chromosomes that are most important for the skin cell fate
23.
There are fundamental differences between amplification of DNA by PCR and DNA replication in cells. When DNA is
replicated in vitro by polymerase chain reaction (PCR) ______________ is used to break the hydrogen bonds that hold
complementary DNA strands together. In a cell the strands are separated by _______________.
a. heat, DNA polymerase
b. DNA polymerase, heat
c. heat, helicase
d. helicase, heat
e. heat, DNA ligase
24.
In a fate map experiment, scientists label a cell of an embryo, for example by injecting the cell with a nontoxic dye.
Scientists document which cells are labeled later in the development of the embryo. Which of the answers below best
describes the general goal of this type of experiment?
a. To determine whether one cell can induce a change in another cell.
b. To identify the genes that are important for specific developmental events.
c. To determine whether gene functions are redundant.
d. To determine which cells are required for specific developmental events.
e. To determine the fates and positions of cells descended from specific blastomeres.
25.
Intestinal and kidney epithelial cells differ mainly because
a. intestinal cells have deleted DNA for kidney-specific genes.
b. they express different genes.
c. they use different genetic codes.
d. they use different ribosomes.
e. they contain different chromosomes.
26.
Which of the following is an example of extracellular matrix?
A) Collagen
B) Fibronectin
C) Chitin
D) All of the above
E) 1 and 2 above
F) None of the above
27.
Which of the following is true about collagen?
1) It is a triple helix made up of identical subunits.
2) It is a triple helix made up of different types of subunits.
3) There are at least 27 different collagen proteins in humans.
4) Differential gene expression helps regulate which collagens are expressed in specific tissues and locations in the body.
5) All of the above
6) 1 and 3 above
7) None of the above
28.
Why would it be important to have epithelial layers lining compartments such as the intestine?
A) To secrete ECM onto the surface
B) To strictly control what substances cross the barrier
C) To create a smooth surface
D) To have a strong covering
E) To create a slippery surface
29.
Which general type of animal tissue would have the most extensive ECM? A) epithelial
B) cardiac
C) muscle
D) nervous
E) endocrine
F) connective tissues
30.
Intestinal and kidney epithelial cells differ mainly because...
A) intestinal cells have deleted DNA for kidney-specific genes.
B) they use different genetic codes.
C) they use different ribosomes.
D) they contain different chromosomes.
E) they express different genes.
31.
What group of proteins plays a key role in controlling the program of developmental changes?
A) motor proteins
B) transporter proteins
C) synaptic proteins
D) restriction endonucleases
E) transcription factors
32.
Plants are different from animals because plant development ...
A) does not involve stem cells
B) does not involve transcriptional hierarchies
C) does not involve differential gene expression
D) does not invlove apoptosis
E) does not involve cell proliferation
F) does not involve cell migration
33.
A pluripotent stem cell is capable of:
A) generating skin cells, but not nerve cells
B) generating epidermal cells, but not mesoderm or endodermal cells
C) generating cell types from skin and brain, but not muscle
D) generating muscle and intestinal cells, but not neurons
E) generating neurons, skin, muscle and lung cells.
34.
Morphogens, such as Bicoid, are not distributed evenly throughout developing organisms and function as transcription
factors that activate particular genes at specific times. How do morphogens activate genes?
1) high concentrations of morphogens affect gene expression
2) low concentrations of morphogens affect gene expression
3) absence of morphogens affect gene expression
4) All of the above
5) None of the above
35.
The primary functions of the small intestine include:
A) secretion of insulin for regulation of blood sugar levels
B) production of gastric acid and pepsinogen
C) production of enzymes that are involved in digestion of macromolecules D) production of neurotransmitters
D) synthesizing essential amino acids
36.
Which of the following is an essential macronutrient that plants need to build the four major macromolecules: proteins,
nucleic acids, carbohydrates, and lipids?
A) iron
B) zinc
C) phosphorus
D) molybdenum
E) copper
37.
Which of the following is the primary site of nutrient absorption in the mammalian digestive system?
A) pharynx
B) stomach
C) large intestine
D) small intestine
E) pancreas
38.
All of the following statements about digestion are correct EXCEPT:
A) During digestion, nucleic acids are split into nucleotides.
B) During digestion, fats are split into monoglycerides and fatty acids.
C) Most digestion occurs in the stomach.
D) During digestion, polysaccharides and disaccharides are split into monosaccharides.
E) Digestion is catalyzed by enzymes.