Tissue Engineering Multiple Choice Questions on “Cell Adhesion”.
1. ____________ is the process by which cells interact and attach to neighboring cells through specialized molecules of the cell surface.
A. Cell Migration
B. Cell Division
C. Cell Development
D. Cell adhesion
Answer: D
Clarification: The process by which cells interact and attach to each other is termed as cell adhesion. This is done through specialized cells on their surface. Cell adhesion could either be due to direct contact between the surfaces of the cells or by indirect interaction, in which cells attach to the extracellular matrix (ECM).
2. __________ a in the process of cell adhesion.
A. Cell receptors
B. Transmembrane proteins
C. Protease
D. Cytokinins
Answer: A
Clarification: The interactions among the cell-adhesion molecules (CAMs) result in a phenomenon called Cell adhesion. In general, the cell-adhesion molecules are the trans-membrane proteins located on the cell’s surface.
3. _____________ is a hemophilic cell-adhesion molecule.
A. Cadherins
B. Integrins
C. Selectins
D. Antibody
Answer: A
Clarification: Cell adhesion molecules (CAMS) are classified into four categories: selectins, integrins, cadherins, and immunoglobulins (Ig). Each of the CAMs has a particular function and they recognize a different ligand. Cadherins and immunoglobulins are homophilic CAMs, since they bind to the same type of CAMs on another cell, while integrins and selectins are heterophilic CAMs that bind to different types of CAMs.
4. Cell adhesion is also essential for infectious organisms, such as bacteria or viruses, to cause diseases.
A. TRUE
B. FALSE
Answer: A
Clarification: Variations in cell adhesion can cause disruptions in major cellular processes and cause a number of diseases like cancer and arthritis. Cell adhesion is also essential for infectious organisms, such as bacteria or viruses, to cause diseases.
5. Plants cells adhere closely to each other and are connected through __________
A. plasmodesmata
B. stomata
C. parenchyma
D. stroma
Answer: A
Clarification: Plants cells adhere closely to each other and are attached through the plasmodesmata. These are channels crossing the plant cell walls and connect the cytoplasm of neighboring plant cells.
6. HIV has an adhesion molecule termed hemagglutinin that binds to its ligand CD4.
A. TRUE
B. FALSE
Answer: B
Clarification: Viruses have molecules aing in adhesion of viral cells to the host cells. The influenza virus has adhesion molecules termed hemagglutinin on its surface; it helps in the recognition of sugar sialic ac molecules on the molecules on the host cell surface. HIV has an adhesion molecule called gp120 that binds to the CD4 ligand.
7. Selectins mediate the movement of keratinocytes.
A. TRUE
B. FALSE
Answer: B
Clarification: Selectins are a category of specialized CAMs that are involved in transient cell-cell adhesion occurring in the circulatory system. They mainly mediate the movement of the WBCs in the bloodstream by allowing the white blood cells to sle on endothelial cells through reversible bindings of selections.
8. __________ have adhesion molecules on their cell surface termed bacterial adhesins.
A. Prokaryotes
B. Reptiles
C. Birds
D. Humans
Answer: B
Clarification: Prokaryotes have adhesion molecules on their cellular surface termed bacterial adhesins. These adhesins have the ability to recognize a number of ligands present on the host’s cellular surface and also the components in the Extracellular matrix (ECM).
9. Cells have specific CAMs that will bind to molecules in the extracellular matrix.
A. TRUE
B. FALSE
Answer: A
Clarification: Cells create ECM by filling the surrounding extracellular space with molecules. Cells have specific CAMs that will bind to molecules in the ECM and link the matrix to the intracellular cytoskeleton. These links are termed as cell-matrix junctions.
10. _________ link extracellular matrix to keratin intermediate filaments.
A. Integrins
B. Cadherins
C. Immunoglobulins
D. Selectins
Answer: A
Clarification: In hemesmosomes, integrins attach to ECM proteins called laminins in the basal lamina, which is the ECM secreted by the epithelial cells. Integrins link ECM to keratin intermediate filaments. Hemesmosomes are important in maintaining the structural stability of epithelial cells by anchoring them together indirectly through the extracellular matrix.
11. What type of CAM has been represented in the diagram?
A. Integrins
B. Cadherins
C. Immunoglobulins
D. Selectins
Answer: A
Clarification: Integrins are composed of hetero-dimers of α and β subunits associated non-covalently. In the case of vertebrates there are eighteen α and eight β subunits. These can conform into 24 different receptors along with various properties of subunit binding and tissue distribution.
12. What type of CAM has been represented in the diagram?
A. Integrins
B. Cadherins
C. Immunoglobulins
D. Selectins
Answer: C
Clarification: The members of the immunoglobulin family are characterized by their immunoglobulin fold which is a characteristic trait shared by all of them.
13. In focal adhesions, integrins attach ___________
A. integrins
B. cadherins
C. immunoglobulins
D. selectins
Answer: A
Clarification: In central bonds, integrins join fibronectins, a part in the extracellular network, to actin fibers inse cells. Connector proteins, for example, talins, vinculins, α-actinins and filamins, structure a complex at the intracellular space of integrins and tie to actin fibers. This multi-protein complex connecting integrins to actin fibers is significant for a get together of flagging edifices that go about as a sign for cell development and cell motility.
14. Dysfunction of cell adhesion occurs during cancer metastasis.
A. TRUE
B. FALSE
Answer: A
Clarification: Brokenness of cell bond happens during disease metastasis. Loss of cell-cell attachment in metastatic tumor cells enables them to get away from their site of root and spread through the circulatory framework.
15. What is the marked entity in the given diagram?
A. Adhesion protein
B. Enzyme
C. Amino ac
D. Membrane-Lip
Answer: A
Clarification: Cell adhesion molecules (CAMs) are a subset of adhesion proteins that are available at the cell membrane surface. It has a binding site that helps in binding with the ligands on the outer surface of the cell.
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