Ovalle: Netter's Essential Histology, 2nd Edition

Chapter 1: The Cell

Test Bank

MULTIPLE CHOICE

	1.	Rough endoplasmic reticulum (RER) in the cell cytoplasm is intensely stained by hematoxylin because hematoxylin:
a.	Attaches to lipids in RER membranes	
b.	Binds readily to RNA	
c.	Catalyzes the precipitation of ribosomes into a dense, readily stained matrix	
d.	Is an acid dye and binds to acidophilic ribosomal proteins	
e.	Reacts with carbohydrate molecules of integral membrane proteins	

ANS:	B
The metal ions associated with hematoxylin impart a positive charge to the dye, which enables it to bind to negatively charged molecules like acids (e.g., ribonucleic acid). See 1-1.

	2.	Staining a specimen using immunocytochemical methods detects the presence of:
a.	Lipids with multiple double bonds between carbon atoms	
b.	Organelles with an above average optical density	
c.	Specific types of carbohydrates	
d.	Specific proteins	
e.	Specific sequences of RNA	

ANS:	D
Antibodies are typically used to bind to specific proteins; specific sequences of RNA are detected by in situ hybridization histochemical techniques. See 1-23.

	3.	Desmin is an intermediate filament protein that is specifically localized in:
a.	Astrocytes	
b.	Cardiac muscle	
c.	Lymphocytes	
d.	Macrophages	
e.	Simple cuboidal epithelial cells	

ANS:	B
Cells in each of the four classes of tissue produce intermediate filaments specific for that class of cells; desmin is the intermediate filament specific for muscle.  See 1-24.

	4.	Numerous mitochondria possessing unusual tubular cristae are a distinguishing anatomic feature of:
a.	Exocrine pancreatic acinar cells	
b.	Nerve cells of the cerebral cortex	
c.	Pancreatic islet cells	
d.	Skeletal muscle cells	
e.	Steroid-secreting cells in the adrenal cortex	

ANS:	E
Mitochondria possess enzymes required for critical steps in steroid synthesis; why these enzymes are associated with tubular cristae is not yet known.  See 1-12.

	5.	Tay-Sachs disease results from abnormalities in:
a.	Keratin	
b.	Lysosomes	
c.	Microtubules	
d.	Mitochondria	
e.	Rough endoplasmic reticulum	

ANS:	B
Tay-Sachs disease results from a deficiency of lysosomal hexosaminidase, leading to an accumulation of gangliosides within cells. See 1-18.

	6.	Claudin is a protein that is functionally important in:
a.	Gap junctions	
b.	Hemidesmosomes	
c.	Intermediate junctions	
d.	Synapses	
e.	Tight junctions	

ANS:	E
Claudin is essential for the formation of membrane fusions in tight junctions.  See 1-5.

	7.	A function of the Golgi complex includes:
a.	Degradation of abnormal proteins	
b.	Destruction of hydrogen peroxide	
c.	Glycosylation of proteins	
d.	Storage of calcium	
e.	Translation of messenger RNA	

ANS:	C
Golgi stacks are the site of O-linked glycosylation of proteins and for the addition of carbohydrate molecules such as sialic acid.  See 1-17.

	8.	Lipofuscin is a brownish pigment that may accumulate in:
a.	Lipid droplets	
b.	Lysosomes	
c.	Mitochondria	
d.	Smooth endoplasmic reticulum	
e.	The cell nucleus	

ANS:	B
Lipofuscin represents the indigestible remnants of structures hydrolyzed in lysosomes.  See 1-18.