Untitled Quiz

A network of protein filaments extending throughout the cytoplasm of eukaryotic cells.

False

<p>To provide structural support and to be involved in various types of cellular movement.</p> Signup and view all the answers

<p>7 nanometers</p> Signup and view all the answers

<p>Actin-bundling proteins and proteins that organize actin networks.</p> Signup and view all the answers

<p>Parallel bundles and contractile bundles.</p> Signup and view all the answers

<p>They lack a nucleus and organelles, making it easier to isolate the plasma membrane and associated proteins.</p> Signup and view all the answers

<p>It forms a network with actin filaments that helps maintain the biconcave shape of red blood cells.</p> Signup and view all the answers

<p>It links the spectrin-actin network to the plasma membrane by binding to spectrin and a transmembrane protein called band 3.</p> Signup and view all the answers

<p>It links spectrin-actin junctions to the transmembrane protein glycophorin.</p> Signup and view all the answers

<p>It links actin filaments to transmembrane proteins in the plasma membrane, which in turn link to the extracellular matrix.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>Large actin bundles that are contractile bundles, cross-linked by alpha-actinin and stabilized by tropomyosin.</p> Signup and view all the answers

<p>Sites of attachment for stress fibers to the extracellular matrix, mediated by transmembrane proteins called integrins.</p> Signup and view all the answers

<p>Cell-cell contacts that form a continuous adhesion belt around each cell, mediated by transmembrane proteins called cadherins.</p> Signup and view all the answers

<p>Fingerlike extensions of the plasma membrane that are abundant on cells involved in absorption.</p> Signup and view all the answers

<p>A layer of microvilli on the apical surface of epithelial cells lining the intestine.</p> Signup and view all the answers

<p>It helps attach actin bundles to the plasma membrane in association with the calcium-binding protein calmodulin.</p> Signup and view all the answers

<p>Extensions of moderate width that are responsible for phagocytosis and movement of amoebas.</p> Signup and view all the answers

<p>Broad, sheetlike extensions at the leading edge of fibroblasts.</p> Signup and view all the answers

<p>Thin projections of the plasma membrane supported by actin bundles.</p> Signup and view all the answers

<p>Extension of the leading edge, attachment of the leading edge to the substratum, and retraction of the rear of the cell into the cell body.</p> Signup and view all the answers

<p>They regulate the formation of cell surface protrusions in response to extracellular stimuli.</p> Signup and view all the answers

<p>They activate WASP proteins, which then stimulate the Arp2/3 complex.</p> Signup and view all the answers

<p>To provide structural support and to be involved in various types of cellular movement, including organelle transport and cell division.</p> Signup and view all the answers

<p>Tubulin dimers, which consist of alpha-tubulin and beta-tubulin.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>It helps initiate microtubule assembly at the centrosome.</p> Signup and view all the answers

<p>The alternating cycles of growth and shrinkage that microtubules undergo in response to GTP hydrolysis and the binding of new tubulin subunits.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>They inhibit microtubule assembly and are used as experimental tools and in cancer treatments.</p> Signup and view all the answers

<p>They inhibit microtubule polymerization and are used in cancer chemotherapy.</p> Signup and view all the answers

<p>It stabilizes microtubules, which also blocks cell division.</p> Signup and view all the answers

<p>Proteins that regulate the dynamic behavior of microtubules.</p> Signup and view all the answers

<p>They accelerate microtubule growth by increasing the incorporation of GTP-bound tubulin.</p> Signup and view all the answers

<p>They dissociate GTP-bound tubulin from the plus end of microtubules, leading to microtubule shrinkage or catastrophe.</p> Signup and view all the answers

<p>They rescue microtubules from catastrophe by stopping disassembly and restarting growth.</p> Signup and view all the answers

<p>A microtubule-organizing center in animal cells, from which most microtubules extend outward.</p> Signup and view all the answers

<p>A structure formed by microtubules extending outward from duplicated centrosomes during mitosis, which controls chromosome separation and distribution to daughter cells.</p> Signup and view all the answers

<p>Plant cells lack centrosomes, and microtubules instead form an array underlying the plasma membrane, which is involved in plant cell wall synthesis.</p> Signup and view all the answers

<p>It is a ring-shaped structure in the centrosome that helps initiate microtubule growth, bypassing the rate-limiting nucleation step.</p> Signup and view all the answers

<p>Cylindrical structures found in most animal cell centrosomes, containing nine triplets of microtubules.</p> Signup and view all the answers

<p>Kinesins and dyneins.</p> Signup and view all the answers

<p>Towards the plus end.</p> Signup and view all the answers

<p>Towards the minus end.</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>It moves along microtubules towards the minus end, responsible for transporting cargo towards the minus end of microtubules.</p> Signup and view all the answers

<p>To transport macromolecules, vesicles, and organelles through the cytoplasm.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>It helps position the Golgi apparatus near the centrosome.</p> Signup and view all the answers

<p>Microtubule-based projections of the plasma membrane that are responsible for movement in many eukaryotic cells.</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>It links the A and B tubules of each doublet, helping keep the microtubules in proper arrangement.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>It anchors the minus end of microtubules in cilia and flagella, similar in structure to a centriole.</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>The centrosome replicates, and the resulting centrosomes migrate to opposite poles of the cell, creating the two poles of the spindle.</p> Signup and view all the answers

<p>Kinetochore microtubules, chromosomal microtubules, polar microtubules, and astral microtubules.</p> Signup and view all the answers

<p>They attach to condensed chromosomes at the centromeres, stabilizing them.</p> Signup and view all the answers

<p>They connect to chromosome ends via chromokinesin.</p> Signup and view all the answers

<p>They are not attached to chromosomes but are stabilized by overlapping with each other in the center of the cell.</p> Signup and view all the answers

<p>They extend outward from the centrosomes with the plus ends anchored in the cell cortex.</p> Signup and view all the answers

<p>It connects chromosomal microtubules to chromosome ends, ensuring proper alignment at the metaphase plate.</p> Signup and view all the answers

<p>Anaphase A, where chromosomes move towards the poles along kinetochore microtubules, and Anaphase B, where spindle poles separate.</p> Signup and view all the answers

<p>They depolymerize and shorten kinetochore microtubules, pulling chromosomes towards the poles of the cell.</p> Signup and view all the answers

<p>They cross-link overlapping interpolar microtubules and move them towards the plus end, pushing spindle poles apart.</p> Signup and view all the answers

<p>It is anchored to the cell cortex and moves along astral microtubules towards the minus end, pulling spindle poles apart.</p> Signup and view all the answers

<p>Filaments that have diameters intermediate between actin filaments and microtubules.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>Keratins, vimentin, desmin, neurofilament proteins, and nuclear lamins.</p> Signup and view all the answers

<p>They provide structural support in epithelial cells.</p> Signup and view all the answers

<p>It forms a network that extends from the nucleus towards the cell periphery, providing structural support in various cell types.</p> Signup and view all the answers

<p>It connects the Z discs of individual contractile elements in muscle cells.</p> Signup and view all the answers

<p>They provide structural support for long axons in neurons.</p> Signup and view all the answers

<p>They form a meshwork that underlies the nuclear membrane, providing structural integrity and regulating nuclear shape.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>It plays a central role in filament assembly by forming a coiled coil with another polypeptide.</p> Signup and view all the answers

<p>They determine the specific functions of the intermediate filament protein.</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>Junctions between adjacent cells that involve the attachment of keratin filaments to dense protein plaques.</p> Signup and view all the answers

<p>It mediates the attachment of keratin filaments to dense protein plaques in desmosomes.</p> Signup and view all the answers

<p>Junctions that connect epithelial cells to underlying connective tissue, involving the attachment of keratin filaments to integrins via plakins.</p> Signup and view all the answers

<p>It binds actin filaments and microtubules, forming bridges between them and between intermediate filaments, increasing the mechanical stability of the cell.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>A genetic disorder that causes skin blistering from cell lysis after minor trauma, caused by mutations in keratin genes that interfere with the assembly of keratin filaments.</p> Signup and view all the answers