WorksheetsCytoskeleton
Total questions: 20
Worksheet time: 3600secs
Bacterial Actin Homologs contribute to the cell shape by serving as a scaffold to direct the synthesis of the peptidoglycan cell wall. Which of the following is/are Actin homolog/s in bacteria ?
Mre B and Mbl
Fts Z
Dna K
Dna J
Which of the following is not a component of the cytoskeleton of a eukaryotic cell ?
Microfilaments
Mitochondria
Intermediate Filaments
Microtubules
Actin filaments and microtubules share all of the following properties , except :
they are involved in cell motility
they are intrinsically polar structures
they can associate with motor proteins
they are assembled from subunits that are heterodimners.
Choose the statement that is not correct for the cytoskeletal protein actin :
α -actins are found in various types of muscles.
Polymerisation of pure actin in vitro requires GTP.
actin filaments have a slow growing minus end and a fast growing plus end.
Cytochalasins are the inhibitors for actin polymerisation.
Beating of cilia is regulated by :
Actin
Myosin
Cofilin
Nexin
In an attempt to study the transport of secretory vesicles containing insulin along with mic4rotubules in cultured pancreatic cells , how would treatment with "Colcemid" affect the transport of these vesicles ?
Colcemid induces polymerisation of microtubules which in turn would activate vesicular transport.
Polymerisation of microtubules is inhibited by colcemid ,which in turn would inhibit the transport of secretary vesicles.
colcemid inhibits the vesicular trafficking through inactivation of v-SNARE protein.
colcemid activates t-SNARE proteins and in turn activated vesicular transport.
In a neuron , proteins and membranes are primarily synthesised in the cell body. These materials must be transported down the axon to the synaptic region using microtubules in an anterograde fashion. Such axonal transport is directed by :
Dynein
Kinesin
Both
Myosin
Myosin molecules that assemble into Bipolar Filaments in the Muscle are :
Myosin-1
Myosin-2
Myosin-3
Myosin-4
The erythrocyte membrane cytoskeleton consists consists of a meshwork of proteins underlying the membrane. The principal component spectrin has α , β -subunits which assemble to form tetramers. The cytoskeleton is anchored to the membrane through linkages with the transmembrane proteins band 3 and glycophorin C. The cytosolic domain of band 3 also serves also serves as the binding site of glycolytic enzymes such as glyceraldehyde 3- phosphate dehydrogenase. Analysis of the blood sample of a patient with haemolytic anemia shows spherical red blood cells. The patient carries :
a mutation in glycophorin C
A mutant spectrin with increased tetramerization propensity.
mutant β spectrin defective in αβ dimerisation ability.
mutant glyceraldehyde 3- phosphate dehydrogenase.
Cytochalasins are the drugs that inhibit actin polymerisation into microfilaments . Colcichine blocks tubulin subunit interaction. Which effect these drugs show on the mammalian cell cycle ?
Cytochalasin inhibits Mitosis and Colchicine inhibits Cytokinesis.
Colchicine inhibits Mitosis and Cytochalasin inhibits Cytokinesis.
Both inhibits mitosis
Both inhibits Meiosis.
Regarding microtubule assembly and disassembly during cell division , which will be the most appropriate answer ?
once formed , kinetochore microtubules depolymerize at the plus ends throughout mitosis.
once formed , kinetochore microtubules polymerize at the plus ends throughout mitosis.
kinetochore microtubules polymerize at their their plus ends up to anaphase , at which point they begin to depolymerise.
kinetochore microtubules polymerize at their their minus ends up to cytokinesis , at which point they depolymerise.
P. Kinesin walks from (-) end to (+) end
Q. dynein walks from (+) end to (-) end
R. kinesin walks on microtubules.
S. dynein walks on microtubules
Which of the choices are true ?
P , Q , R , S
P , Q
Q , R
P , S
Treadmilling of actin filaments refers to :
net assembly at both plus and minus ends.
net assembly at plus ends and net disassembly at minus ends.
net disassembly at plus ends and net assembly at minus ends.
net disassembly at both plus and minus ends.
The diameter of Microtubules , Microfilaments and Intermediate filaments are :
25nm , 7 nm , 11nm respectively.
7nm , 11nm , 25nm respectively.
7nm , 25nm , 11nm respectively.
25nm , 11nm 7nm respectively.
Actin is bound to______ , while tubulin is bound to ______.
ATP , GTP respectively.
GTP , ATP respectively.
The function of Cap Z and Tropomodulin includes :
Cap Z prevents polymerisation and Tropomodulin prevents Depolymerisation of Microfilaments.
Cap Z prevents depolymerisation and Tropomodulin prevents polymerisation of Microfilaments.
Cap Z prevents polymerisation and Tropomodulin prevents Depolymerisation of Microtubules.
Cap Z prevents depolymerisation and Tropomodulin prevents polymerisation of Microfilaments.
Actin cross linking protein is :
Formin
Spectrin
Cofillin
Profillin
The movement of chloroplast is by :
Microfilaments
Microtubules
Intermediate filament
All of the above
Phallodin drug is responsible for preventing :
Depolymerisation of Microfilaments
Depolymerisation of Microtubules
polymerisation of Microfilaments
polymerisation of Microtubules
ALS disorder is due to abnormal assembly of :
Microfilaments
microtubules
intermediate filaments
None
