Question 1

Which component of animal connective tissue is primarily responsible for resisting compressive forces?

Accepted Answer

Glycosaminoglycans and proteoglycans

Question 2

What is the main function of tight junctions in epithelial sheets?

Accepted Answer

Seal neighboring cells together to prevent leakage of extracellular molecules

Question 3

Which protein family mediates mechanical attachment between cells in adherens junctions and desmosomes?

Accepted Answer

Cadherins

Question 4

A mutation in the APC gene leads to constitutive activation of which signaling pathway, resulting in over-proliferation of gut precursor cells?

Accepted Answer

Wnt signaling pathway

Question 5

Which equation best describes the tensile strength provided by collagen fibers in connective tissue?

Accepted Answer

$$F = \sigma \cdot A$$

Question 6

What is the role of integrins in cell-matrix interactions?

Accepted Answer

They bind to fibronectin and tether the extracellular matrix to the cytoskeleton

Question 7

Which of the following best describes the process by which procollagen is converted to mature collagen?

Accepted Answer

Procollagen is cleaved by procollagen proteinases outside the cell, allowing self-assembly into fibrils

Question 8

Which junction is most critical for synchronous contraction and bending of epithelial sheets during embryonic development?

Accepted Answer

Adherens junction

Question 9

Stem cell self-renewal and differentiation are regulated by environmental signals. Which of the following is NOT a mechanism involved in stem cell niche regulation?

Accepted Answer

Direct phosphorylation of DNA by kinases

Question 10

Which of the following statements about cancer is TRUE?

Accepted Answer

Cancer cells proliferate in defiance of normal restraints and can invade and colonize new territories

Question 11

Which equation represents the exponential growth of a tumor, given a doubling time of $$t_d$$ days?

Accepted Answer

$$N(t) = N_0$ \cdot 2$$^{\frac{t}$${t_d}}$$

Question 12

Which of the following is a property of pluripotent embryonic stem cells?

Accepted Answer

They can give rise to all tissues in the body

Question 13

Which cell junction allows direct electrical and metabolic coupling between neighboring cells, such as in cardiac muscle?

Accepted Answer

Gap junction

Question 14

Which of the following best explains why loss-of-function mutations in tumor suppressor genes are recessive?

Accepted Answer

Both copies of the gene must be lost to drive a cell toward cancer

Question 15

Which of the following is a plausible consequence of a gain-of-function mutation in a proto-oncogene?

Accepted Answer

Increased cell proliferation and potential for cancer development

Question 16

Which equation describes the rate of cell migration influenced by collagen fiber alignment?

Accepted Answer

$$v = \mu \cdot F$$

Question 17

Which of the following is TRUE regarding induced pluripotent stem cells (iPSCs)?

Accepted Answer

They are generated by forced expression of Oct4, Sox2, Klf4, and cMyc in differentiated cells

Question 18

Which of the following is a function of glycosaminoglycans (GAGs) in connective tissue?

Accepted Answer

Resist compressive forces and regulate passage of molecules

Question 19

Which junction anchors keratin filaments in an epithelial cell to the basal lamina?

Accepted Answer

Hemidesmosome

Question 20

Which of the following best describes the function of the basal lamina in epithelial tissues?

Accepted Answer

It provides a foundation for epithelial cells and separates them from underlying connective tissue

Cell Communities: Tissues, Stem Cells, and Cancer

Guida di studio - Domande di pratica

Study guide - Flashcard