Question 1

Which of the following best describes the role of cadherins in adherens junctions?

Accepted Answer

They mediate cell-cell adhesion by binding to cadherins on adjacent cells, linking to actin filaments via catenins.

Question 2

Which protein links cadherins to actin filaments in the cytoskeleton, as shown in the adherens junction structure?

Accepted Answer

Catenin

Question 3

Mechanotransduction at adherens junctions involves which of the following processes?

Accepted Answer

Sensing mechanical stress and generating biochemical signals in response

Question 4

Desmosomes differ from adherens junctions in that desmosomes:

Accepted Answer

Link to intermediate filaments via specialized cadherins

Question 5

Which of the following statements about tight junctions is correct?

Accepted Answer

They prevent the free passage of molecules between epithelial cells.

Question 6

Gap junctions allow the passage of molecules up to what approximate size?

Accepted Answer

$$5,000$$ daltons

Question 7

Which of the following extracellular matrix (ECM) components is a glycoprotein that helps organize the ECM and bind cells to it?

Accepted Answer

Laminin

Question 8

Hemidesmosomes are specialized structures that:

Accepted Answer

Anchor epithelial cells to the basal lamina via integrins and intermediate filaments

Question 9

In the epidermis, which layer contains the stem cells responsible for regeneration?

Accepted Answer

Basal cell layer

Question 10

Which of the following best describes the process of asymmetric stem cell division?

Accepted Answer

One daughter cell self-renews while the other differentiates.

Question 11

The size of a stem cell niche can limit the number of stem cells because:

Accepted Answer

It determines how many cells can receive the necessary signals for self-renewal.

Question 12

Which of the following is true about embryonic stem (ES) cells?

Accepted Answer

They are pluripotent and can give rise to most cell types in the organism.

Question 13

Induced pluripotent stem (iPS) cells are generated by introducing which set of transcription factors?

Accepted Answer

Oct4, Sox2, Klf4, Myc

Question 14

Which of the following best explains why iPS cell technology is significant for medical research?

Accepted Answer

It enables the generation of patient-specific pluripotent cells for disease modeling and potential therapies.

Question 15

A mutation in the gene encoding connexin proteins would most likely affect which cellular structure?

Accepted Answer

Gap junctions

Question 16

Which of the following ECM components is primarily responsible for providing tensile strength to tissues?

Accepted Answer

Fibrillar collagen

Question 17

A patient with a genetic defect in integrin proteins would most likely have problems with:

Accepted Answer

Cell-matrix adhesion and anchoring to the basal lamina

Question 18

Which of the following best describes the function of the 'adhesion belt' in epithelial cells?

Accepted Answer

It links actin filaments of adjacent cells via cadherins, providing mechanical stability.

Question 19

During the process of reprogramming fibroblasts into iPS cells, which genes are activated first?

Accepted Answer

Somatic genes

Question 20

Which of the following is a real-world application of iPS cell technology?

Accepted Answer

Screening for therapeutic compounds using patient-specific cells

Cell Junctions and Stem Cells: Structure, Function, and Regulation

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