cell bio exam III key

the following DNA nuclease produces straight, blunt ended cuts:
A. EcoRI
B. HindIII
C. HaeIII
D. NotI

dissociation of dsDNA into single strands:
A. (b or c)
B. requires a high pH
C. requires a low pH
D. requires high temperatures
E. (a or b)

DNA from different individuals varies in:
A. STRs
B. (a and c)
C. RFLPs
D. (a and b)
E. rRNAs

leaky mitochondrial membranes:
A. can be easily repaired
B. are necessary for oxidative phosphorylation
C. result in cell death

cell membranes from the following organelles are exposed to the external environment:
A. mitochondria
B. golgi apparatus
C. peroxisomes
D. none of the above

phosphatidylcholine contains:
A. a quaternary ammonium ion
B. only saturated fatty acids
C. no phosphodiesters
D. a carboxyl ion

phosphatidylserine contains:
A. no phosphodiesters
B. a steroid group
C. terminal amino acid
D. an ammonium ion

K⁺ ion concentrations:
A. are 30 times higher inside the cell than outside
B. are 10 times higher inside the cell than outside
C. are 30 times higher outside the cell than inside
D. are 20 times higher outside the cell than inside

the passive transporter for glucose:
A. works with the concentration gradient
B. works with the electrochemical gradient
C. works against the concentration gradient
D. works against the membrane potential

the maximum resting membrane potential for an animal cell is approximately:
A. -0.2 V
B. +0.2 V
C. -0.02 V
D. -2V

the following dye is used to visualize DNA bands after separation on agarose gels.
A. ethidium bromide
B. neutral red
C. coumassie blue
D. indocyanine green

the polymerase chain reaction requires:
A. a thermal cycler
B. dNTPs
C. Taq polymerase
D. all of the above

after 3 cycles of PCR, the number of dsDNA strands resulting from one initial dsDNA strand is:
A. 16
B. 8
C. 2
D. 4

reagents necessary to produce a recombinant DNA construct for use in E. coli include:
A. a dsDNA fragment insert
B. a dsDNA plasmid
C. a restriction nuclease
D. DNA ligase
E. all of the above

from what is cDNA made?
A. genomic ssDNA
B. dsRNA
C. mRNA
D. none of the above

the restriction nuclease HindIII produces:
a. straight blunt ended cuts
b. staggered cuts with "sticky ends"

DNA can be quantitated by measuring absorbance at _______nm:
A. 470
B. 280
C. 260
D. 490 

Taq polymerase is obtained from the organism:
A. thermus aquaticus
B. bacillus thuringiensis
C. bacillus thermoaquaticus
D. none of the above

eucaryotic systems for recombinant gene expression include:
A. pichia pastoris
B. (a and b)
C. escherichia coli
D. sacchromyces cerevisiae

patterns of gene expression in different cell types can be determined by:
A. sequencing rRNAs
B. sequencing genomic DNA
C. replacing genes of interest with reporter genes

genetic manipulations include:
A. gene replacement with a mutant gene
B. gene knockout
C. gene addition
D. all of the above

a convenient source of natural membranes for experimentation is:
A. leukocytes
B. red blood cells
C. brain tissue

membrane scaffolding proteins include:
A. actin
B. spectrin
C. (a and c)
D. myelin
E. (b and c)

integral membrane proteins can be extracted with:
A. ethanol
B. SDS
C. triton x-100
D. (a and c)

bacterial rhodopsin uses _________ to absorb light energy.
A. chlorophyll
B. cytochromes
C. retinal
D. heme

cells can complex glycolipids:
A. as recognition motifs
B. (b and c)
C. in the inner membrane leaflet
D. as energy sources

Concanavalin A is a(n):
A. structural protein
B. transporter
C. lectin
D. enzyme

Membrane channels are selectively permeable due to:
A. internal diameters
B. (a and b)
C. specific amino acids lining the lumen

Ions with hydration shells can be transported by channels:
a. true
b. false

voltage gated Ca2+ channels:
A. inhibit synaptic signaling
B. stimulate neurotransmitter release
C. maintain resting membrane potential

membrane channel control mechanisms include:
A. stress gating
B. (a and b)
C. ligand gating

The nernst equation for membrane potenial is:
A. V = 62 X log10(co/ci)
B. V = (Ci/Co)
C. V = 62 X log10(ci/co)
D. V = IR

the resting membrane potential is dependent primarily on _______ on both sides of the membrane. 
A. [Na+]
B. [H+]
C. [K+]
D. [Ca2+]

the primary advantage of cDNA is:
A. regulatory sequences
B. lack of introns
C. more active promoters
D. none of the above

restriction mapping of genomal segments:
A. is done with multiple nucleases
B. is done with single nuclease
C. (b and c)
D. generates overlapping sequences

Microarrays:
A. require computers to use
B. are prepared by hand
C. use radioactively labeled cDNA probes
D. (b and d)
E. use fluorescent cDNA probes

site directed mutagenesis requires restriction nucleases:
a. true
b. false

the glucose transporter:
A. (a and c)
B. transports L-glucose
C. transports D-glucose
D. works with the concentration gradient
E. (a and b)

the action potential in neurons is generated by:
A. K+ channels
B. Na+ channels
C. (a and b)
D. H+ channels

the Na+/K+ pump:
A. is dependent on ATP
B. transports Na+ out of the cell, K+ into the cell
C. transports K+ out of the cell, Na+ out of the cell
D. (a and b)
E. (a and c)

animal cells expend approximately _______% of their total ATP to transport Na+:
A. 40%
B. 10%
C. 30%
D. none of the above

coupled membrane transport:
A. can pump two ligands into the cell simultaneously
B. can exchange one ligand for another across the membrane
C. (a and b)
D. none of the above

the active glucose transporter:
A. pumps glucose with the concentration gradient
B. (a and b)
C. (b and c)
D. pumps glucose against the concentration gradient
E. uses a K+ electrochemical gradient

In intestinal epithelial cells:
A. glucose if pumped into and out of the cell by active transport
B. glucose is pumped in by active transport and out by passive transport
C. glucose is pumped in by passive transport and pumped out by active transport

plant cells modulate their ionic balance:
A. by pumping K+ out of the cell
B. (b and c)
C. by pumping H+ out of the cell
D. by pumping Na+ out of the cell

auditory hair cell sterocilia transform sound waves into an electrical signal with this ion channel:
A. Na+
B. K+
C. H+
D. Ca++

the action potential in neurons has a maximum amplitude of about:
A. +60 mV
B. +40 mV
C. -60 mV
D. - 40 mV

the toxin ouabain:
A. blocks the voltage gated calcium channel
B. inhibits K+ binding to the Na+/K+ pump
C. blocks inhibitory signals
D. blocks signal delivery at neuromuscular junctions

neurotransmitters include:
A. glutamate
B. serotonin
C. glycine
D. (a and b)
E. all of the above

the toxin curare:
A. causes muscle spasms and convulsions
B. blocks inhibitory signals
C. causes muscle paralysis
D. (a and b)