cell bio exam III key

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

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

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

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

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. only saturated fatty acids
B. a carboxyl ion
C. a quaternary ammonium ion
D. no phosphodiesters

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

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

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

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

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

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. 2
B. 16
C. 8
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. 490 
B. 260
C. 280
D. 470

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. escherichia coli
B. sacchromyces cerevisiae
C. pichia pastoris
D. (a and b)

patterns of gene expression in different cell types can be determined by:
A. sequencing genomic DNA
B. sequencing rRNAs
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. red blood cells
B. leukocytes
C. brain tissue

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

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

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

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

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

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

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

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

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

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

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

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. generates overlapping sequences
D. (b and c)

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

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

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

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

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

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

In intestinal epithelial cells:
A. glucose is pumped in by active transport and out by passive transport
B. glucose if pumped into and out of the cell by active 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. by pumping Na+ out of the cell
C. (b and c)
D. by pumping H+ out of the cell

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

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

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

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

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