Cell Bio FInal

In a disease, the un-normal accumulation of acetylcholine in the neuromuscular junction causes muscle spasm. You are designing a drug to release this symptom. Which drug should have the highest specificity? A. Inhibit ACh receptor B. Inhibit AChE C. Inhibit voltage-gated Ca2+ channel D. Inhibit voltage-gated Na+ channel

A. Inhibit ACh receptor

You designed drugs for each targets. Which one would have the lowest specificity? A. Na+/K+ pump B. H+pump C. Voltage-gated Na+channel

A. Na+/K+ pump

an animal cell that has 8 chromosomes in G1phase. How many of each of the following structures will the cell have during mitosis?s ister chromatids / centromeres / kinetochores / centrosomes A. 8/16/8/2 B. 16/16/16/2 C. 16/8/16/2 D. 16/2/16/16

B. 16/16/16/2

You found a piece of gene sequence from NCBI database: 5'- ATACGT - 3'Which of the following is the Sequence of mRNA? A. 5'- ATACGT - 3' B. 5'- AUACGU - 3' C. 5'- ACGTAT - 3' D. 5'- ACGUAU - 3' E. 5'- TGCATA - 3' F. 5'- UGCAUA - 3'

B. 5'- AUACGU - 3'

In a experiment you add a start transfer-signal sequence to the N-terminus and a GFP tag to the C-terminus of a cytosolic protein. You expect to see the green fluorescence A. In cytosol B. In nucleus C. In the lumen of ER D. Associated with ER membrane

D. Associated with ER membrane

Which of the following statements about cancer is FALSE? a) A mutation in a single cancer-critical gene is sufficient to convert a normal cell into a cancer cell. b) Carcinogens cause cancer by changing the nucleotide sequence of DNA. c) Cancers are caused by the accumulation of a series mutations on oncogenes and tumor suppressor genes. d) Many cancer cells have abnormal chromosomes representing genetic instability.

a) A mutation in a single cancer-critical gene is sufficient to convert a normal cell into a cancer cell.

Which of the following transcription factors is needed to convert an adult cell into an induced pluripotent stem (iPS) cell? a) All of the above b) Sox2 c) Klf4 d) Oct4

a) All of the above

An adult hematopoietic stem cell found in the bone marrow ______________________. a) can undergo self-renewing divisions for the lifetime b) will occasionally produce epidermal cells when necessary c) can produce only red blood cells d) can produce only white blood cells

a) can undergo self-renewing divisions for the lifetime

Which of the following molecule has the highest permeability to plasma membrane? a) steroid hormone b) water c) glucose d) proton

a) steroid hormone

Given the sequence of a coding strand: 5' - GCATTCGTGGGTAG - 3' Give the sequence of the mRNA and label the 5' and 3' ends. a) 5'-CGUAAGCACCCAUC-3' b) 5'- GCAUUCGUGGGUAG -3' c) 5'-CUACCCACGAAUGC-3' d) 5'-CTACCCACGAATGC-3'

b) 5'- GCAUUCGUGGGUAG -3'

During the action potential propagation on neuron cell, which of the following best describes the voltage changes in one plasma membrane region? a) -60 mV → -40 mV → 0 mV → -40 mV → -60 mV b) 0 mV → +40 mV → +60 mV → +40 mV → 0 mV c) -40 mV → 0 mV → +40 mV → 0 mV → -40 mV d) -60 mV → -40 mV → 0 mV → +40 mV → -60 mV

d) -60 mV → -40 mV → 0 mV → +40 mV → -60 mV

Which of the following statements is CORRECT? a) A loss-of-function mutation in an oncogene makes the coding protein hyperactive.. b) Loss-of-function mutations in a tumor suppressor gene make the coding protein hyperactive. c) Loss-of-function mutation in one allele of tumor suppressor gene may be sufficient to stimulate cell division. d) A gain-of-function mutation in only one allele of oncogene can stimulate cell survival or division.

d) A gain-of-function mutation in only one allele of oncogene can stimulate cell survival or division.

Researchers studying vesicular transport assembled several transport components in vitro (in a test tube). They set up the stabilized microtubules, then added vesicles and kinesin. When they put everything together, there was no movement of transport vesicles along microtubule. What were they missing? a) Ca2+ b) SNARE c) GTP d) ATP

d) ATP

Which of the following statements about fluorescence microscopy is FALSE? a) Phase contrast microscopy can directly visualize cells without fixation and staining. b) The resolution limit of a regular fluorescence microscopy is around 200 nm. c) GFP protein can be used to track specific proteins in living cells. d) The excitation wavelength of GFP is longer than its emission wavelength.

d) The excitation wavelength of GFP is longer than its emission wavelength.

What will NOT happen if too many misfolded proteins are accumulated in the ER? a) More chaperon proteins will be produced to correct misfolded proteins. b) Protein synthesis will be reduced to avoid adding more misfolded proteins. c) Cell will attempt suicide if the problem can't be solved in time. d) The misfolded proteins will be packaged and secreted outside to keep the cell healthy.

d) The misfolded proteins will be packaged and secreted outside to keep the cell healthy.

You found a piece of gene sequence from NCBI database: 5'- ATACGT - 3'Which of the following is the Coding sequence? A. 5'- ATACGT - 3' B. 5'- AUACGU - 3' C. 5'- ACGTAT - 3' D. 5'- ACGUAU - 3' E. 5'- TGCATA - 3' F. 5'- UGCAUA - 3'

A. 5'- ATACGT - 3'

Which of the following statements is TRUE? A. All cells will respond to the endocrine signals as endocrine molecules are broadcast throughout the body. B. Extracellular signal molecules that are hydrophilic must bind to a cell-surface receptor so as to signal a target cell. C. To function, all extracellular signal molecules must be transported by their receptor across the plasma membrane into the cytosol. D. A receptor bound by one type of signal molecule mediates only one kind of cell response. E. Each type of receptor induces an independent signaling pathway and avoids interference with other intracellular signaling pathways.

B. Extracellular signal molecules that are hydrophilic must bind to a cell-surface receptor so as to signal a target cell.

The unwanted cytosolic proteins are sent to lysosome for digestion and re-use. A. True B. False

B. False

During a drug screen you find a compound that can block the binding of Ca2+to troponin. Predict the effect of this drug. A. Muscle spasm B. Muscle paralysis C. Hypnosis D. No effect

B. Muscle paralysis

To design a drug that can inhibit LDL uptake, which protein should NOT be chosen as the target? A. tubulin B. kinesin C. dynein D. clathrin

B. kinesin

Suppress of apoptosis can promote cancer cell survival. Which of the following compound could be an anti-cancer drug? A. A compound that inhibits Bax B. A compound that inhibits Bad C. A compound that inhibits Bcl2 D. A compound that inhibits Fas-receptor

C. A compound that inhibits Bcl2

Which one has the highest percentage of unsaturated phospholipids? A. rattlesnake B. Penguin C. salmon

C. salmon

Which one has the lowest percentage of cholesterol? A. rattlesnake B. Penguin C. salmon

C. salmon

The following genes could become oncogene except . A.E2F B.Bcl2 C.BAD D.mTOR

C.BAD

Which of the following muta;ons would lead to an excess in the amount of glucose in skeletal muscle cells? A. A GPCR mutant form that loses the binding ability to adenaline B. A G-protein mutant form that loses GTP-binding ability C. A PKA mutant form that loses cAMP-binding ability D. A PKA mutant form in which the inhibitory subunits lose the binding ability to the kinase subunits.

D. A PKA mutant form in which the inhibitory subunits lose the binding ability to the kinase subunits.

A IgG antibody is a . A. Monomer B. Dimer C. Trimer D. Tetramer

D. Tetramer

Select the option below that most accurately predicts the relative rates of diffusion of these molecules across a phospholipid bilayer (fastest to slowest).alanine estrogen ethanol sodium A. alanine > ethanol > sodium > estrogen B. sodium > ethanol > alanine > estrogen C. estrogen > ethanol > sodium > alanine D. estrogen > ethanol > alanine > sodium

D. estrogen > ethanol > alanine > sodium

The sequence of a membrane protein contains several signal sequences shown in figure. Predict which terminus will eventually localize in the cytosol. A. N-terminus B. C-terminus C. both N- and C- D. none

D. none

Which type of proteins can be removed from membrane most easily? A. transmembrane B. monolayer associated C. lipid-linked D. protein-attached

D. protein-attached

Proteins that are fully translated in the cytosol do not end up in __. A. the cytosol B. the mitochondria C. the interior of the nucleus D. transport vesicles

D. transport vesicles

Which of the following 20 aa sequences is likely a crossmembranestructure? A. PPPPPPNNNNNNNNPPPPPP B. NNNNNNNNNNNNNNNNNNNN C. PNPNPPPPPNNNPPNNNNNP D. NNPNNPNNPNNPNNPNNPNN E. A & B F. B & D

F. B & D

To study the function of keratin, which of the following models can be chosen? A. Yeast B. Drosophila C. Zebra fish D. Mouse E. B, C and D F. C and D G. All of them

F. C and D

Which of the following statements is FALSE? a) Most G-protein-coupled receptors are multipass transmembrane proteins with 7 α-helixes. b) Activated G protein produces 3 separate subunits that function independently. c) Each calmodulin can bind to 4 calcium ions. d) Receptor tyrosine kinases (RTK) always form dimers after binding with signal molecules.

b) Activated G protein produces 3 separate subunits that function independently.

Which of the following hydrocarbon tail would yield the most highly mobile phospholipid (listed as number of carbons and number of double bonds, respectively)? a) 20 carbons with 2 double bonds b) 24 carbons with 1 double bond c) 15 carbons with 2 double bonds d) 16 carbons with no double bonds

c) 15 carbons with 2 double bonds

What would happen if you add a ER-specific signal sequence to the amino-terminal end of a normally cytosolic protein? a) The ER signal sequence will not be recognized and the protein will remain in the cytosol. b) The ER signal sequence will be cleaved off and the protein will remain in the cytosol. c) The protein will be delivered to the ER and fully synthesized in ER. d) The protein will be fully synthesized in cytosol and then be delivered into the ER.

c) The protein will be delivered to the ER and fully synthesized in ER.

Which of the following statements is FALSE? a) A polypeptide chain starts with an amino group and ends in a free carboxyl group. b) hydrogen bonds along the protein backbone allow the formation of α helices and β sheets. c) The sequence of the atoms in the polypeptide backbone varies among different proteins. d) In a higher temperature, more chaperons can be synthesized to guide the folding of proteins.

c) The sequence of the atoms in the polypeptide backbone varies among different proteins.

Which of the following statements about protein transport to mitochondria is TRUE? a) Proteins are translocated into the mitochondria as completely folded proteins. b) A protein has to be transported though the outer membrane and the inner membrane separately. c) The signal that directs a protein to mitochondria is always cleaved off from the final folded protein. d) All the proteins in mitochondria need to be imported from cytosol.

c) The signal that directs a protein to mitochondria is always cleaved off from the final folded protein.

Which of the following microscopy has the highest resolution? a) SEM b) fluorescence microscopy c) phase contrast d) TEM

d) TEM

Which of the following statements is TRUE? A. Covalent bonds can be established by condensation reaction, which release water molecules. B. Covalent bonds help assemble large protein complexes from protein subunits. C. Noncovalent bonds form only between different molecules D. Heat can unfold a protein molecule and broke it into small peptides.

A. Covalent bonds can be established by condensation reaction, which release water molecules.

Plant cells need to maintain a proper membrane fluidity when the environmental temperature changes. Which of the following changes in plant cell membrane components will happen when time goes into the winter? A. more unsaturated phospholipids B. less unsaturated phospholipids C. more cholesterol D. less cholesterol E. more unsaturated phospholipids and less cholesterol F. less unsaturated phospholipids and more cholesterol xG. no change

A. more unsaturated phospholipids

Which one has the lowest percentage of unsaturated phospholipids? A. rattlesnake B. Penguin C. salmon

A. rattlesnake

Proteins that are fully translated in the cytosol and lack a sorting signal will end up in A. the cytosol B. the mitochondria C. the interior of the nucleus D. transport vesicles

A. the cytosol

You want to design a drug to inhibit neuron transduction. Which of the following protein complexes can NOT be a target? A. Na+/K+ pump B. H+pump C. Voltage-gated Na+channel

B. H+pump

In a disease, the un-normal accumulation of acetylcholine in the neuromuscular junction causes muscle spasm. You are designing a drug to release this symptom. Which of the following strategies should NOT work? B2. A. Inhibit ACh receptor B. Inhibit AChE C. Inhibit voltage-gated Ca2+ channel D. Inhibit voltage-gated Na+ channel

B. Inhibit AChE

You have generated antibodies that recognize the extracellular domain of the Ca2+-pump. Adding these antibodies to living animal cells blocks the active transport of Ca2+from the cytosol into the extracellular environment. What do you expect to observe with respect to intracellular Ca2+level? A. Dramatically increases in the cytosol B. Remains low in the cytosol C. Decreases in ER D. Increases in Golgi

B. Remains low in the cytosol

You found a piece of gene sequence from NCBI database: 5'- ATACGT - 3'Which of the following is the Sequence of template strand? A. 5'- ATACGT - 3' B. 5'- AUACGU - 3' C. 5'- ACGTAT - 3' D. 5'- ACGUAU - 3' E. 5'- TGCATA - 3' F. 5'- UGCAUA - 3'

C. 5'- ACGTAT - 3'

Which of the following compounds can NOT be a poten=al an=-cancer drug? A. A compound that blocks associa=on of Ras-GEF with RTK B. A compound that inhibits Ras-GEF C. A compound that inhibits Ras-GAP D. A compound that inhibits MAPKKK

C. A compound that inhibits Ras-GAP

Q: Which of the following DNA fragments has the highest Tm? A. ATCGGCTAATCG B. ATATCGTTTAAA C. CCCGGGTAGGCCGCGG D. CATACGTTTAAATTAAAT

C. CCCGGGTAGGCCGCGG

The distribution of in cell membrane is symmetric. A. Phospholipids B. Glycolipids C. Cholesterols D. Phospholipids and Cholesterol E. All of them

C. Cholesterols

You made a transgene encoding a cell surface protein fused with GFP at C-terminal and will express it in cultured cells. Predict the cellular components that are labeled by green fluorescence. A. cell membrane B. Golgi, vesicles, cell membrane C. ER, Golgi, vesicles, cell membrane D. ER, Golgi, vesicles, endosome, lysome, cell membrane E. cytosol, ER, Golgi, vesicles, cell membrane F. nucelus, cytosol, ER, Golgi, vesicles, cell membrane

C. ER, Golgi, vesicles, cell membrane

In a experiment you add a ER-signal sequence to the N-terminus and a GFP tag to the C-terminus of a cytosolic protein. You expect to see the green fluorescence A. In cytosol B. In nucleus C. In the lumen of ER D. Associated with ER membrane

C. In the lumen of ER

To design a drug that can inhibit cancer cell migration, which protein may NOT be chosen as the target? A. Actin B. ARP C. Kinesin D. Myosin E. Integrin

C. Kinesin

A hematopoie8c stem cell in the bone marrow is _________. A. renewed from ES cells B. Pluripotent C. Multipotent D. A and B E. A and C F. terminally differentiated

C. Multipotent

Which of the following happens when a G-protein-coupled receptor activates a G protein? A. The β subunit exchanges its bound GDP for GTP. B. The GDP bound to the α subunit is phosphorylated to form bound GTP. C. The α subunit exchanges its bound GDP for GTP. D. It acGvates the α subunit and inacGvates the βγ complex.

C. The α subunit exchanges its bound GDP for GTP.

Which of the following statements is TRUE? A. DNA sequence of a gene on chromosomes can be directly translated into protein sequences B. All genes start with ATG C. All mRNAs start with AUG D. Protein syntheses start with Met E. All proteins start with Met

D. Protein syntheses start with Met

To study the function of lamin, which of the following models can be chosen? A. Yeast B. Drosophila C. Zebra fish D. Mouse E. B, C and D F. C and D G. All of them

E. B, C and D

In an experiment, you treated cells with a drug that blocks ATP synthesis, which of the following processes will be arrested immediately? A. microtubule assembly B. exocytosis C. actin filament assembly D. cell migration E. A, B F. C, D G. B, C, D

G. B, C, D

Which of the following compounds can be a potential anti-cancer drug? A compound that inhibits A. p53 B. Rb C. E2F D. p21 E. S-Cdk F. A and B G. C and E

G. C and E

Which of the following proteins participate in the release of neurotransmitters? Consider vesicle docking and fusion during exocytosis. a) All of them b) Rab c) SNARE d) tethering protein

a) All of them

What would be the consequence of inactivation of E2F? a) Cells would be unable to enter the S phase. b) Cells would develop cancer. c) The Rb protein would become activated. d) Cells would enter S phase.

a) Cells would be unable to enter the S phase.

You use GFP tag to track a protein that will ultimately be secreted from the cell. If all is functioning well, in which order (from first to last) do you expect to find the protein in the cell until it is secreted? a) ER → Golgi → secretory vesicle → outside of the cell b) nucleus → ER → Golgi → secretory vesicle → outside of the cell c) ER → Golgi → endosome → outside of the cell d) Golgi → ER → secretory vesicle → outside of the cell

a) ER → Golgi → secretory vesicle → outside of the cell

Which of the following statements about enzyme is FALSE? a) Enzymes speed reactions by decreasing delta-G (energy difference between reactant and product). b) Enzymes generally remain unchanged after finishing catalyzing a reaction. c) The interaction between enzyme and substrate is generally mediated by noncovalent bonds. d) Enzymes do not change the equilibrium of reactions.

a) Enzymes speed reactions by decreasing delta-G (energy difference between reactant and product).

Irradiated mammalian cells usually stop dividing and arrest at a G1 checkpoint. Place the following events in the order in which they occur. I. production of p21 II. DNA damage III. inhibition of cyclin-Cdk complexes IV. activation of p53 a) II-IV-I-III b) I-II-III-IV c) II-I-IV-III d) II-IV-III-I

a) II-IV-I-III

Cell movement involves the coordination of many events in the cell. Which of the following phenomena is NOT required for cell motility? a) Influx of Ca2+ into cytoplasm. b) Nucleation of new actin filaments. c) Myosin-mediated contraction at the rear of the moving cell. d) Integrin association with the extracellular environment.

a) Influx of Ca2+ into cytoplasm.

Which group of enzymes control protein activate by adding phosphate groups to the protein? a) Kinase b) Protease c) Ligase d) Phosphatase

a) Kinase

Which of the following statement is TRUE? a) New phospholipids are synthesized at the cytosolic side of ER. b) Incorporation of cholesterol increases the fluidity of membrane. c) Sugars are added to glycolipids at the cytosolic side of Golgi. d) An α-helix containing 20 amino acids must be a transmembrane structure.

a) New phospholipids are synthesized at the cytosolic side of ER.

A particular strain of yeast produces strains with a mutant cdc2 (M-Cdk) gene, resulting in little to no production of the M-Cdk protein kinase. As a result, what would be expected? a) None of these. b) These cells will enter M phase. c) These cells will have chromosome condensation. d) These cells will have the nuclear envelope disperse.

a) None of these.

Which statement about chemical synapses is TRUE? a) Synapse converts electronical signal to chemical signal then converts it back to electronical signal. b) The presynaptic cell and postsynaptic cell are connected by tight junctions. c) All of them. d) Neurotransmitters are released by the presynaptic cell and absorbed by the postsynaptic cell.

a) Synapse converts electronical signal to chemical signal then converts it back to electronical signal.

Which of the statements below about intermediate filaments is TRUE? a) They can be anchored to the plasma membrane at a type of cell-cell junction. b) They can be found in the cytoplasm and the nucleus of all eukaryotic cells. c) They are strength filaments with about 25 nm in diameter. d) They are made of globular subunits.

a) They can be anchored to the plasma membrane at a type of cell-cell junction.

A cell with mutated lamins that cannot be phosphorylated in M phase will be unable to a) disassemble its nuclear lamina at prometaphase. b) reassemble its nuclear envelope at telophase. c) begin to grow microtubules for spindle assembly. d) condense its chromosomes at prophase.

a) disassemble its nuclear lamina at prometaphase.

The members of the steroid hormone receptor family __________________. a) interact with signal molecules that diffuse through the plasma membrane. b) are cell-surface receptors c) function as monomers d) are found only in the nucleus

a) interact with signal molecules that diffuse through the plasma membrane.

Which of the following compounds can be a potential anti-cancer drug? a) A compound that activates Ras-GEF b) A compound that activates Ras-GAP c) A compound that activates MAPKK d) A compound that activates mTOR

b) A compound that activates Ras-GAP

Which of the following statements is FALSE? a) Cancer cells proliferate indefinitely, presumably related with the stabilization of telomeres. b) A loss-of-function mutation of telomerase will convert a normal cell to a cancer cell. c) Telomerase carries a RNA template, synthesizes and extends template DNA strand at telomere. d) Somatic cells only divide a limited number of cycles, likely due to the shorten of telomeres.

b) A loss-of-function mutation of telomerase will convert a normal cell to a cancer cell.

Which of the following statements is TRUE for Notch signaling? a) Delta is a paracrine ligand that binds to Notch receptor locally. b) Delta binding induces cleavage of Notch receptor. c) To silence the signaling, the nuclear Notch fragment shuttles back to the plasma membrane. d) The Delta-Notch complex enters nucleus and functions as transcription facto

b) Delta binding induces cleavage of Notch receptor.

Highly concentrated ethanol can be used for sterilization. Why can ethanol can kill bacteria? a) It alters the amino acid sequences of proteins. b) It denature proteins by unfolding them. c) It unfold proteins through disrupting covalent bonds. d) It denature proteins by digesting them into amino acids.

b) It denature proteins by unfolding them.

Which of the following is FALSE of the sodium-potassium pump? a) It helps create electrochemical gradients across the cell membrane. b) It transports 2 sodium ions out of the cell and 3 potassium ions into the cell each time. c) The sodium gradient created by the pump is used for glucose absorption in the gut. d) It has enzyme activity to catalyze hydrolysis of ATP to ADP.

b) It transports 2 sodium ions out of the cell and 3 potassium ions into the cell each time.

Which of the following statements is TRUE? a)All hydrophilic molecules form only hydrogen bonds with water molecules. b) Phospholipids have both hydrophilic and hydrophobic components. c) Hydrophobic interactions are most likely to occur on the surface of a water-soluble protein. d) Ionic bonds are strong bonds that make molecules un-soluble in water.

b) Phospholipids have both hydrophilic and hydrophobic components.

A malignant tumor is more dangerous than a benign tumor because its cells ________________. a) attack and phagocytose neighboring cells b) invade other tissues c) proliferate faster d) cause neighboring normal cells to mutate

b) invade other tissues

Which of the following proteins can move cargos through an actin filament? a) kinesin b) myosin c) filamin d) dynein

b) myosin

Progression through the cell cycle requires a cyclin to bind to a Cdk because _________. a) without cyclin binding, a cell-cycle checkpoint will be activated b) the binding of a cyclin to Cdk is required for Cdk enzymatic activity c) the cyclins are the molecules with the enzymatic activity in the complex d) cyclin binding inhibits Cdk activity until the appropriate time in the cell cycle

b) the binding of a cyclin to Cdk is required for Cdk enzymatic activity

Place the following events of M phase into the correct order. 1. Alignment of the chromosomes at the spindle equator 2. Attachment of microtubules to chromosomes 3. Breakdown of nuclear envelope 4. Reformation of the nuclear envelope 5. Condensation of the chromosomes 6. Separation of sister chromatids a) 3,5,2,1,6,4 b) 5,3,1,2,6,4 c) 5,3,2,1,6,4 d) 3,5,1,2,6,4

c) 5,3,2,1,6,4

Which of the following statements is FALSE? a) A nucleosome contains a histone core with DNA wrapped around it approximately two times. b) The N-terminal tails of core histones can be covalently modified. c) A histone core contains two of each of the core histones (H1, H2, H3, H4). d) Chromatins are present in eukaryotic cells, but not in prokaryotic cells.

c) A histone core contains two of each of the core histones (H1, H2, H3, H4).

Which of the following statements about apoptosis is TRUE? a) Cells that constitutively express Bcl2 will be more prone to undergo apoptosis. b) The Fas ligand and Fas receptor work to inhibit apoptosis. c) Apoptosis can be promoted by the release of cytochrome c into the cytosol from mitochondria. d) Bax and Bak promote apoptosis by binding to procaspases in the apoptosome.

c) Apoptosis can be promoted by the release of cytochrome c into the cytosol from mitochondria.

In DNA replication the lagging strand is synthesized discontinuously at the replication fork because a) DNA polymerase removes the last few nucleotides synthesized whenever it stops. b) DNA polymerase always falls off the template DNA every ten nucleotides or so. c) DNA polymerase can polymerize nucleotides only in the 5'-to-3' direction. d) DNA polymerase needs RNA primer to start DNA synthesis.

c) DNA polymerase can polymerize nucleotides only in the 5'-to-3' direction.

Which of the following statements about antibodies is TRUE? a) Antibodies adapt different overall shapes so that they can bind to different antigens. b) Each antibody is composed of two polypeptide chains. c) Disulfide bonds are formed between the polypeptide chains. d) α helices establish domains in the polypeptide chains

c) Disulfide bonds are formed between the polypeptide chains.

Which of the following statements about genome is FALSE? a) Many human genes are believed to undergo alternative splicing. b) Most of the human genes contain intron. c) Most of the human genome code for proteins. d) Human genome is distributed on 46 chromosomes in most normal cells.

c) Most of the human genome code for proteins.

Which of the following statements about membrane-enclosed organelles is TRUE? a) The endomembrane system contains all of the membrane-enclosed organelles. b) All the membrane-enclosed organelles are surrounded by a double membrane. c) The membrane of nucleus is always continuous with the membrane of ER. d) The nucleus is the only organelle that contains DNA.

c) The membrane of nucleus is always continuous with the membrane of ER.

Which of the following neurotoxins directly blocks the removal of acetylcholine neurotransmitter? a) Botulinum Toxin b) Tetrodotoxin c) VX d) Curare

c) VX

Which of the following is NOT one of the pathways activated by RTKs? a) RAS-MAPK b) Bad-Bcl2 c) cAMP-PKA d) Akt-Tor

c) cAMP-PKA

A multipotent cell _________. a) can only give rise to stem cells b) is considered to be terminally differentiated c) can give rise to some cell types in the body d) can give rise to all the tissues and cell types in the body

c) can give rise to some cell types in the body

The activity of a protein can be posttranscriptionally regulated by any of the methods except . a) ligand binding that induces allosteric conformation b) covalent modification c) controlling gene expression d) protein interaction

c) controlling gene expression

In a muscle cell, which internal organelle would you expect to be particularly abundant? a) lysosome b) chloroplast c) mitochondria d) Golgi

c) mitochondria

Embryonic stem cells are such a powerful possible treatment for disease because they are______. a) well understood b) derived from fetuses c) pluripotent d) multipotent

c) pluripotent

When a terminally differentiated cell in an adult body dies, it can typically be replaced in the body by a stock of ________. a) embryonic stem cells b) induced pluripotent cells c) proliferating precursor cells that are derived from adult stem cells d) cells more apically located than the terminally differentiated cells

c) proliferating precursor cells that are derived from adult stem cells

In a synapse, neurotransmitter molecules are released through . a) crossmembrane transport b) receptor mediated exocytosis c) regulated exocytosis d) constitutive exocytosis

c) regulated exocytosis

Which type of RNA in the following controls mRNA splicing? a) rRNA b) mRNA c) snRNA d) tRNA

c) snRNA

In the cell containing a loss-of-function mutation of the separase gene, which of the following phenotypes can be predicted? a) The condensing complex will not be assembled. b) The cohensin complex will not be assembled. c) Mitotic chromosomes will not be aligned correctly in metaphase. d) Sister chromatids will not be segregated after metaphase.

d) Sister chromatids will not be segregated after metaphase.

Which of the following means of transport would most likely be used for moving an amino acid from a low concentration on the outside to a high concentration on the inside of a cell? a) active transport through a transporter or a channel b) passive transport through a transporter c) active transport through a channel d) active transport though a transporter

d) active transport though a transporter

Which gene mutation give rise to unchanged amino acid sequence in a protein? a) missence mutation b) nonsense mutation c) frameshift mutation d) silent mutation

d) silent mutation

Which of the following statements is false ? A. CO2and O2are water-soluble molecules that diffuse freely across cell membranes. B. Ion channels are one of the passive forms of cross-membrane transport. C. Transporters are similar as channels, except that they have larger gates, allowing folded proteins as well as smaller organic molecules to pass through them. D. Cells expend energy in the form of ATP hydrolysis to maintain ion concentrations inside the cell that differ from those found outside the cell.

C. Transporters are similar as channels, except that they have larger gates, allowing folded proteins as well as smaller organic molecules to pass through them.

Which of the following mutations may suppress cell proliferation? A. a mutation on APC complex that prevents its binding with β-catenin B. a mutation on APC complex that permanently inactivate its function C. a mutation in the NLS (nuclear localizaton signal sequence) of β-catenin D. All of them

C. a mutation in the NLS (nuclear localizaton signal sequence) of β-catenin

To design a drug that can inhibit insulin secretion, which protein should NOT be chosen as the target? A. tubulin B. kinesin C. dynein D. clathrin

C. dynein

If the anaphase promoting complex (APC/C) is temperature sensitive (active at 30 degree, but inactive at 40 degree), shifting to the higher temperature (40 degree) at the start of M phase would prevent which of the following? a) DNA replication. b) Degradation of M-Cdk. c) Entrance into M phase. d) Degradation of securin and separation of sister chromatids

d) Degradation of securin and separation of sister chromatids

Which of the following statements is TRUE? a) In anaphase A, chromosome movement is driven by shorten of aster microtubules. b) Anaphase A is driven by motor proteins kinesin and dynein. c) In anaphase A, both kinetochore microtubules and interpolar microtubules shorten. d) In anaphase B, microtubules associated with the cell membrane shorten

d) In anaphase B, microtubules associated with the cell membrane shorten

Which of the following would you expect to see in a cell that has been exposed to colchicine? a) Disappearance of the nucleus b) An increased synthesis of cellular proteins c) Inability to regulate cell size d) Mis-organized endomembrane system

d) Mis-organized endomembrane system