Cell Biology 2nd Edition by Pollard Test bank

<< CFIN 3 3rd Edition by Besley Test Bank Essential Calculus 2nd Edition James Stewart Test Bank >>
Product Code: 222
Availability: In Stock
Price: $24.99
Qty:     - OR -   Add to Wish List
Add to Compare

Cell Biology 2nd Edition by Pollard Test bank

Description

Pollard: Cell Biology, 2nd Edition

Test Bank

Chapter 6: Research Strategies

MULTIPLE CHOICE

1. Which one of the following statements about an allele with a conditional mutation is true?
a.
It is mutated only under restrictive conditions.
b.
It encodes a gene product that is active or inactive depending on cellular conditions.
c.
It is sensitive to some mutagens but not to others.
d.
It is mutated only under permissive conditions.

ANS: B
The mutation itself is fixed, but its phenotypic expression is conditional.

2. Which one of the following statements about Green Fluorescent Protein (GFP) is NOT true?
a.
GFP can still fluoresce when fused to other proteins.
b.
GFP can be modified to make it fluoresce red, blue or yellow.
c.
To fluoresce, GFP needs chemical energy to be supplied by the host cell.
d.
Once expressed, GFP can be visualized in any living.

ANS: C
No energy is required other than that provided by the light source.

3. Which one of the following statements about classical genetics is NOT true?
a.
It typically involves random mutagenesis.
b.
It can be applied to organisms from bacteria to man.
c.
Working from a known genotype, and unknown phenotype is determined.
d.
It typically involves gene mapping.

ANS: C

4. Which one of the following statements about a dominant-negative mutation is FALSE?
a.
Its phenotype is observed when the corresponding wild-type allele is co-expressed.
b.
It encodes a gene product that is completely inactive.
c.
It encodes a gene-product that impairs the activity of the product of the wild-type allele.
d.
Unlike a simple dominant mutation, its phenotype is not due to haplo-insufficiency.

ANS: B
A dominant negative mutation is a mutation in a gene coding for one subunit of a multi-subunit protein; the mutant subunit assembles with subunits coded for the normal allele, inactivating the total protein.

5. Which of the following is true about gel filtration chromatography?
a.
Any molecules that enter bead pores are permanently retained.
b.
Molecules much larger than pores elute in the void volume.
c.
Small molecules elute first.
d.
Proteins are separated on the basis of shape.

ANS: B
Molecules can enter and exit pores; small molecules elute last; separation is on the basis of size. Molecules larger than pores dont enter pores and come out in the initial eluate (void volume).

6. A two-hybrid assay identifies any proteins that specifically interact with
a.
a defined transcriptional activator.
b.
a defined DNA binding protein.
c.
any defined protein.
d.
any defined DNA sequence.

ANS: C
The assay makes use of a DNA binding protein and transcriptional activator, but it is the defined bait and undefined trap proteins fused to these that must interact to bring about reporter or drug-resistance gene expression.

7. Which one of the following is essential in order to purify a previously unknown molecule responsible for a cellular activity?
a.
An appropriate antibody and/or epitope tag.
b.
Chromatography.
c.
An assay for the cellular activity.
d.
Gel electrophoresis.

ANS: C
Chromatography and electrophoresis are useful but not essential. There cant be an antibody or epitope tag if the molecule is unknown.

8. Which one of the following is FALSE about expression cloning?
a.
A complex cDNA library is introduced into a host cell type.
b.
Host cells can be bacteria or yeast or vertebrate in origin.
c.
Cells may screened with antibodies to the protein of interest or for an expected change of phenotype.
d.
It relies on knowing at least a part of the amino acid or cDNA sequence for the protein of interest.

ANS: D
A feature of expression cloning is that screening is done independently of any knowledge of nucleotide sequence. The screen relies on having a specific assay for the desired protein (e.g., antibody-binding assay).

9. In fluorescence microscopy, simultaneous detection of a protein and a nucleic acid sequence, with antibody and nucleic acid probes, respectively, is difficult because
a.
Two different fluorophores with widely separated emission spectra must be used.
b.
Conditions that denature DNA but not protein in the sample must be used.
c.
Protein and nucleic acid probes interfere with each other.
d.
Labeling of nucleic acids with fluorescent tags impairs their ability to hybridize to complementary sequences.

ANS: B
Nucleic denaturation is required before a nucleic acid probe can bind. Conditions for this (e.g., heating to >65oC) tend to disrupt sites involved for epitope antibody interactions.

10. Which of the following best describes the genetic complementation of a mutant cell?
a.
A wild-type copy of the mutated gene is introduced into the mutant cells.
b.
The phenotype of the mutant is restored to wild-type by introduction of wild-type genetic material from the same species.
c.
The genotype of the mutant is restored to wild-type by introduction of wild-type genetic material from the same species.
d.
The phenotype of the mutant is restored to wild-type by introduction of genetic material from the same or another species.

ANS: D
Genetic material can come form other species (and therefore does not have to be a wild-type copy of the mutated gene) and does not alter the original mutation.

11. Which one of the following statements about reverse genetics is FALSE?
a.
Defined changes to the genotype of an organism are made in order to study the effects on phenotype.
b.
It involves creating mutants by homologous recombination in living.
c.
It makes use of random mutagenesis with chemical mutagens.
d.
It can be applied to human cells.

ANS: C
Chemical mutagenesis is more typical of classical genetic approaches.

12. Which one of the following would be best used to determine the 3-dimensional atomic structure of a newly purified protein?
a.
The amino acid sequence.
b.
NMR spectroscopy.
c.
Reconstruction from multiple electron micrographs of single particles.
d.
Crystallization followed by electron microscopy.

ANS: B
Reconstruction will not give atomic resolution and electron microscopy of crystals is not done; rather, crystals are used for X-ray diffraction.

13. Which one of the following is a disadvantage of using yeasts as model organisms?
a.
They can be diploid or haploid.
b.
Their genomes can be modified experimentally by homologous recombination.
c.
Yeast cells are much smaller than cells of higher eukaryotes.
d.
Their gene products usually have structural and/or functional homologues in higher eukaryotes.

ANS: C
Although small cells tend to multiply faster than large cells, which is an advantage, small cell size is a disadvantage for many microscopic.

Write a review

Your Name:


Your Review: Note: HTML is not translated!

Rating: Bad           Good

Enter the code in the box below:



 

Once the order is placed, the order will be delivered to your email less than 24 hours, mostly within 4 hours. 

If you have questions, you can contact us here