Test
MCBL
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Preguntas del test (50)
1In biological sciences, a p-value equal to or less than what number indicates there is strong evidence against the null hypothesis?
- A0.5
- B0.005
- C0.05
- D0.001
- E1x10-6
2What is the ‘Demarcation Problem’ in the philosophy of science?
- AThe problem of defining “what is, or is not science”
- BThe problem of marking international borders.
- CThe problem of urban graffiti.
- DThe question of morality in science.
3When a biological scientist makes a hypothesis and designs an experiment to test it, all of the inherent assumptions are controlled for:
- AVerdadero
- BFalso
4Generally speaking, scientists should design experiments that attempt to:
- AAffirm the hypothesis
- BDisprove the hypothesis
- CCreate new hypotheses
- DNeither affirm nor disprove the hypothesis
- EA and C
5The chemical analysis of a single stranded DNA containing cell revealed the composition of the four bases as 20% adenine (A) and 30% guanine (G). Which of the following describes its cytosine (C) percentage?
- AEqual to adenine
- BEqual to the sum of adenine and guanine
- CEqual to guanine
- DEqual to the difference between guanine and adenine
- ECannot be calculated from the data provided
6Mutations in our DNA occur at a fairly low rate because:
- AHighly mutated DNA is prone to degradation and removed from cells.
- BHighly mutated DNA is recognized as foreign and phagocytosed
- CMutated DNA is continuously repaired by DNA repair proteins
- DMutated DNA makes proteins that limit the rate of subsequent mutations
- EMutated DNA is in equilibrium with the native DNA
7The daughter DNA strand that is synthesized continuously during replication is known as the:
- ACoding strand
- BLagging strand
- CLeading strand
- DReverse strand
- ETemplate strand
8Helicase _______ during DNA replication
- ARelaxes
- BStabilizes
- CUnwinds
- DDestabilizes
- EA and C
9During DNA replication, the strand associated with Okazaki fragments is:
- ALeading strand
- BLagging strand
- CRNA
- DB and C
- EAll of the above
10Newly synthesize DNA duplex contain:
- ABoth new strands
- BBoth old strands
- COne new strand and one old strand
- DOnly one strand
- ENone of the above
11Nitrogenous base Adenine can pair with:
- AAdenine
- BCytosine
- CGuanine
- DThymine
- ENone of the above
12DNA duplex strands run _____ in relation to each other.
- AAntiparallel
- BParallel
- CPseudoparallel
- DPerpendicular
- ENone of the above
13Free nucleotides triphosphates are added to a new growing DNA strand at:
- AThe 3’ end
- BThe 5’ end
- CAt either 3 of 5’ end
- DNone of the above
14DNA sequences are transcribed by:
- ADNA helicase
- BDNA ligase
- CDNA polymerase
- DRNA ligase
- ERNA polymerase
15If the triphosphate group of free Nucleoside triphosphates A, C, T, and G is attached to the 5’ hydroxyl, which way would you expect polymerase to use those free nucleoside triphosphates to extend a newly synthesizing DNA strand?
- AAt the 3’ end
- BAt the 5’ end
- CAt both ends
16Which of the following is the most appropriate site for the binding of gene regulatory proteins?
- ANuclear membrane
- BPlasma membrane
- CRibosomal RNAs
- DRibosomal proteins
- ESpecific DNA sequences
17Gene splicing refers to:
- ARemoval of introns from DNA
- BRemoval of introns from pre-mRNA
- CRepair of a mutant gene
- DLigation of two distinct DNA sequences
- ELigation of two DNA and RNA sequences
18The following best describes the order, from 5’ to 3’, of various features of a newly-created mRNA:
- A5’ cap, coding region, start codon, termination sequence, stop codon
- B5’ cap, 3’ Untranslated Region, coding region, stop codon
- C5’ cap, 5’ Untranslated Region, start codon, coding region, stop codon
- D5’ Untranslated Region, Markoff sequence, start codon, poly A sequence, coding region
- E5’ cap, poly A sequence, 5’ Untranslated region
19An “epigenetic” modification is:
- AA modification of the DNA sequence that is passed on to progeny
- BA heritable modification of DNA that does not change DNA sequence
- CA heritable modification of non-coding DNA sequence
- DA heritable modification to a tRNA anticodon
- EIs only found in proteins composed of multiple subunits
20Methylation of the DNA base cytosine in C-G pairs affects:
- AThe semi-conservative nature of DNA replication
- BDNA polymerase
- CTranscriptional activity
- DBinding affinity of Okazaki fragments
- Enone of the above
21Which of the following is most associated with genomic imprinting?
- AAcetylation of DNA
- BAcetylation of proteins
- CMethylation of DNA
- DMethylation of proteins
- EPhosphorylation of proteins
22A protein domain:
- AIs a type of tertiary structure held together by disulfide bonds.
- BIs a substructure within a polypeptide chain often associated with a specific function.
- CRefers to functionally related proteins that share a high degree of amino acid homology.
- DRefers to a portion of a polypeptide that undergoes a conformational change when phosphorylated.
- EIs only found in proteins composed of multiple polypeptide subunits.
23Which of the following is true for codons?
- AOne codon codes for multiple amino acids.
- BMultiple codons may code for the same amino acid
- CCodon is defined by a contiguous stretch of 4 nucleotides
- DCodons are recognized by anticodons in ribosomal RNAs
- ECodon recognition occurs by covalent bond formation between mRNA and tRNA
24What best describes ‘modular’ protein domains:
- AProtein domains that fit together with other domains in proteins
- BProtein domains that are unique within a certain protein
- CProtein domains with common architecture in different proteins
- DProtein domains with rare architectures in the same proteins
25Cell membranes are composed of:
- Alipids
- Blipids and carbohydrates
- Clipids and glycerides
- Dlipids, carbohydrates, and proteins
- Echolesterol and proteins
26Phospholipids are:
- Ahydrophilic
- Bhydrophobic
- Cboth hydrophobic and hydrophilic
- Dsaturated fat
- Etrans fat
27An antiporter:
- Atransports different solute species in opposite directions across the membrane
- Btransports the same solute species in opposite directions across the membrane
- Ctransports the same solute species in the same direction across the membrane
- Dtransports different solute species in the same direction across the membrane
- Edoes not transport any solute
28 “Trafficking signals” on various secreted and membrane proteins:
- Aare 3-D globular cellular addresses
- Bare short peptide motifs that act as cellular addresses
- Cmodular domains that act as cellular addresses
- Dall of the above
- Eb and c
29ER associated degradation (ERAD):
- AIs a system of the cell for destroying non-native proteins
- BIs a system of the cell for destroying misfolded proteins
- CIs a system for destroying unassembled subunits of multimeric proteins
- Db and c
- Eall of the above
30Proteins undergoing ERAD are degraded:
- Aby Lysosomes
- Bby cytosolic calcium neutral proteases
- Cby the ubiquitin-proteasome pathway
- Dby acid proteases
- ENone of the above
31Endoplasmic reticulum (ER) retention signals are:
- Aglobular domains that form in the ER
- Bshort peptide motifs that maintain ER localization
- Care modular protein domains that maintain ER localization
- Dassociate with COPII coatomer proteins
- Eassociate with clathrin coat proteins
32ER retention signals in plasma membrane proteins:
- AFunction throughout the secretory pathway
- BFunction as phosphorylation sites
- CImpose permanent ER localization
- DImpose quaternary assembly requirements at the ER level
- ENone of the above
33Which of the following best describes the order of organelles that are traversed by a newly synthesized protein destined to be secreted into the extracellular space?
- AER, Intermediate compartment (IC), trans-Golgi
- BER , IC, cis-, medial-, trans-Golgi, trans-Golgi network (TGN), plasma membrane
- CER, cis-, medial-, trans-Golgi, plasma membrane
- DER, IC, cis-, medial-, trans-Golgi, TGN, extracellular space
- ENone of the above
34With regards to the sorting of proteins to specific cellular destinations, which of the following is false?
- AAll protein synthesis is initiated in the cytoplasm
- BA short polypeptide localization signal is coded for within the gene sequence of proteins that function anywhere but the cytoplasm
- CThose proteins that function in the nucleus and mitochondria are post-translationally sorted
- DAll proteins are co-translationally sorted to the ER as they are being made and then sorted from the ER to a specific destination (only secreted and transmembrane, not all)
- EDepending on where they need to be sorted to, proteins across cellular membranes in different ways
35After endocytosis some receptors are targeted back to the plasma membrane; which of the following paths are they going through before they reach the membrane?
- Aendosomes>recycling endosomes
- Bendosomes>lysosome>secretion vesicles
- Cendosomes>Golgi>ER
- Dendosomes>ER>secretion vesicles
- Eendosomes>ER>lysosomes
36Which of the following is involved in vesicle budding from the ER?
- ACOPI
- BCOPII
- CClathrin
- DRetromers
- EA and C
37SAR1 and ARF1 are involved in which of the following?
- AVesicle targeting
- BCleaving cyclic GMP
- CVesicle coat assembly and budding
- DTransducing a photon into a change in resting potential in the outer segment of retinal rod photoreceptors
- EA and B
38All the major cytoskeletal structures (intermediate filaments, microtubules and micro filaments) are made of smaller subunits. Which is not a subunit found in the associated cytoskeletal element?
- Aactin microfilaments
- Bα-tubulin microtubules
- Ckeratins intermediate filaments
- Dmyosin microfilaments
- E(nuclear) lamins intermediate filaments
39What does the cytoskeleton do?
- AIt is load-bearing
- BIt determines the shape of the cell
- CIt serves as a scaffold imparting signal-specificity
- DIt forms the substrate for intracellular transport
- EA, B, and D
40Kinesin motor proteins:
- AMove along intermediate filaments
- BMove along actin microfilaments
- CMove toward the + end of microtubules
- DMove toward the – end of microtubules
- ENone of the above
41For an extracellular stimulus to produce a change in intracellular signaling:
- ACell surface receptors are essential
- BCell surface receptors are sufficient
- CA and B
- DNone of the above
42Insulin helps absorb glucose by binding to:
- AMembrane g-protein coupled receptors
- BCatalytic receptors
- CGlucose transporters
- DB and C
- ENone of the above
43One of the most important mechanisms by which cells modulate the activity of many different proteins (usually via the action of different kinases) is:
- AMethylation of the protein
- BPhosphorylation of the protein
- CProtein degradation
- DThe protein switching between being bound to GDP and GTP
- EUbiquitination of the protein
44A signal molecule (e.g. ligand) binds to a membrane receptor, which then induces the auto-phosphorylation of the receptor and phosphorylation of other proteins. What types of receptor is this?
- ATyrosine kinase receptor
- BG-protein coupled receptor
- CNuclear steroid receptor
- DIon channel receptor
- EMetabotropic glutamate receptor
45Ligand binding to G-protein coupled receptors can result in which of the following?
- AActivation of phospholipase C
- BActivation of adenylate cyclase
- CRelease of calcium from the ER
- DReceptor trans-autophosphorylation
- EA, B, and C
46Which of the following would homodimerize upon binding of a ligand/signal molecule?
- ATyrosine kinase receptor
- BG-protein coupled receptor
- CNuclear steroid receptor
- DIon channel receptor
- EMetabotropic glutamate receptor
47It is possible for the same extracellular chemical mediator to produce opposite effects on intracellular signaling.
- AFalse because this is not economical
- BThis is true only for synthetic drugs
- CThis is true due to the presence of different receptors for the same ligand
- DB and C
- EFalse because ligands are unique to each receptor
48G protein coupled receptors are:
- AMembrane receptors coupled to enzymes called G-proteins
- BMembrane receptors coupled to g proteins, but g-proteins do not exhibit any enzymatic activity
- CMembrane receptors that are therapeutic targets for majority of drugs on the market
- DA and C
- EB and C
49Neurons have multiple, parallel secretory pathways.
- AVerdadero
- BFalso
50Neurons have multiple, parallel secretory pathways, in order to:
- ACreate independently tunable compartments in dendrites
- BCreate independently tunable compartments in axons
- CNormalize distal/proximal input
- DA and C
- EB and C
Información
- Descripción
- Science Test sobre MCBL, creado por Tina Gettas el 20/04/2019.
- Autor
- Tina Gettas
- Idioma
- English
- Visitas
- 20
- Etiquetas
- Valoración
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