OSSF EXAM 1, 2, 3and 4 NEWEST (TEST BANK) 2026
(GRADED A+ 100% DETAILED VERIFIED ANSWERS)
What must be done to bone before histological processing? - ANSWER✅ It must be
decalcified or demineralized using acid.
What is the process of dehydration in tissue preparation? - ANSWER✅ Gradually replacing
tissue water with an organic solvent, typically ethanol.
What is the embedding material used in histology? - ANSWER✅ Paraffin wax.
How can dehydration and embedding tissue samples distort the tissue structure -
ANSWER✅ Most tissue contains a high volume of water, removing that distorts the
structure causing artifact.
What are the two main stains used in histology? - ANSWER✅ Hematoxylin and Eosin (H&E).
What color does hematoxylin stain and what does it bind to? - ANSWER✅ It stains blue and
binds to negatively charged (acidic) components, such as nuclei.
What color does eosin stain and what does it bind to? - ANSWER✅ It stains pink and binds
to positively charged (basic) components, such as proteins in the cytoplasm.
,What is the purpose of tissue biopsy in histology? - ANSWER✅ To take a 3D tissue sample
and prepare it for 2D examination.
What is the fixative used in tissue fixation? - ANSWER✅ 10% buffered formalin.
What does formalin fixation do to proteins in tissue? - ANSWER✅ Denatures, cross-links,
and precipitates proteins, stabilizing interactions, firming tissue and preventing autolysis.
What is the recommended fixative volume ratio for tissue fixation? - ANSWER✅ 10 parts
formalin to 1 part tissue.
What is the maximum thickness of tissue for effective fixation? - ANSWER✅ 1 cm or less.
What is metachromasia in histology? - ANSWER✅ When basic dyes react and change color,
often appearing more purple.
What is the difference between transmission electron microscopy (TEM) and scanning
electron microscopy (SEM)? - ANSWER✅ TEM studies inner structures and organelles,
while SEM provides 3D images of surfaces.
What are common artifacts in histological sections? - ANSWER✅ Autolysis, tissue
shrinkage, folds, wrinkles, and separation of layers.
,Why do adipose cells appear empty after processing? - ANSWER✅ Alcohol removes fat
and water
How does muscle tissue distort based on the plane of section? - ANSWER✅ Cut in the
same direction as the fiber: elongated nuclei (inner intestinal muscle)
Cut perpendicular to the fiber direction: round nuclei (Outer intestinal muscle)
What is the significance of cytology in histology? - ANSWER✅ It allows for the examination
of tissues or fluids for inflammation, infection, or neoplasia using needle aspiration or cell
scraping.
What are the pros and cons to using cytology instead of biopsy? - ANSWER✅ Pros: fast,
idenfity inflammation
Cons: Nonspecfic, no cell architecture (location)
What is the purpose of immunohistochemistry (IHC)? - ANSWER✅ To detect specific
molecules in tissues using antibody binding.
Which WBCs might have more heterochromatin and why? - ANSWER✅ Neutrophils,
eosionphills, & basophils
They are terminally differentiated and no longer undergoing mitosis
Which WBCs might have more euchromatin and why? - ANSWER✅ Monocytes and
Lymphocytes
, They are metabilically active making new proteins
What is the role of the Golgi apparatus in protein processing? - ANSWER✅ It modifies,
sorts, and packs proteins after translation.
What is an example of post-translational modification that occurs in the golgi? -
ANSWER✅ Glycosylation of outermembrane proteins to form the glycocalyx
What is indicated by a peri-nuclear clearing on cell H&E histology? - ANSWER✅ Presence
of the golgi apparatus
What is the function of ribosomes in cells? - ANSWER✅ They are responsible for protein
synthesis.
How will a high volume of ribosomes appear on histology? - ANSWER✅ Basophilic spots in
the cytoplasm
True or False: mature RBCs have ribosomes - ANSWER✅ False: only immature RBCs have
ribosomes
What is the fate of failed folded proteins? - ANSWER✅ Ubiquination and degradation by
proteosomes
(GRADED A+ 100% DETAILED VERIFIED ANSWERS)
What must be done to bone before histological processing? - ANSWER✅ It must be
decalcified or demineralized using acid.
What is the process of dehydration in tissue preparation? - ANSWER✅ Gradually replacing
tissue water with an organic solvent, typically ethanol.
What is the embedding material used in histology? - ANSWER✅ Paraffin wax.
How can dehydration and embedding tissue samples distort the tissue structure -
ANSWER✅ Most tissue contains a high volume of water, removing that distorts the
structure causing artifact.
What are the two main stains used in histology? - ANSWER✅ Hematoxylin and Eosin (H&E).
What color does hematoxylin stain and what does it bind to? - ANSWER✅ It stains blue and
binds to negatively charged (acidic) components, such as nuclei.
What color does eosin stain and what does it bind to? - ANSWER✅ It stains pink and binds
to positively charged (basic) components, such as proteins in the cytoplasm.
,What is the purpose of tissue biopsy in histology? - ANSWER✅ To take a 3D tissue sample
and prepare it for 2D examination.
What is the fixative used in tissue fixation? - ANSWER✅ 10% buffered formalin.
What does formalin fixation do to proteins in tissue? - ANSWER✅ Denatures, cross-links,
and precipitates proteins, stabilizing interactions, firming tissue and preventing autolysis.
What is the recommended fixative volume ratio for tissue fixation? - ANSWER✅ 10 parts
formalin to 1 part tissue.
What is the maximum thickness of tissue for effective fixation? - ANSWER✅ 1 cm or less.
What is metachromasia in histology? - ANSWER✅ When basic dyes react and change color,
often appearing more purple.
What is the difference between transmission electron microscopy (TEM) and scanning
electron microscopy (SEM)? - ANSWER✅ TEM studies inner structures and organelles,
while SEM provides 3D images of surfaces.
What are common artifacts in histological sections? - ANSWER✅ Autolysis, tissue
shrinkage, folds, wrinkles, and separation of layers.
,Why do adipose cells appear empty after processing? - ANSWER✅ Alcohol removes fat
and water
How does muscle tissue distort based on the plane of section? - ANSWER✅ Cut in the
same direction as the fiber: elongated nuclei (inner intestinal muscle)
Cut perpendicular to the fiber direction: round nuclei (Outer intestinal muscle)
What is the significance of cytology in histology? - ANSWER✅ It allows for the examination
of tissues or fluids for inflammation, infection, or neoplasia using needle aspiration or cell
scraping.
What are the pros and cons to using cytology instead of biopsy? - ANSWER✅ Pros: fast,
idenfity inflammation
Cons: Nonspecfic, no cell architecture (location)
What is the purpose of immunohistochemistry (IHC)? - ANSWER✅ To detect specific
molecules in tissues using antibody binding.
Which WBCs might have more heterochromatin and why? - ANSWER✅ Neutrophils,
eosionphills, & basophils
They are terminally differentiated and no longer undergoing mitosis
Which WBCs might have more euchromatin and why? - ANSWER✅ Monocytes and
Lymphocytes
, They are metabilically active making new proteins
What is the role of the Golgi apparatus in protein processing? - ANSWER✅ It modifies,
sorts, and packs proteins after translation.
What is an example of post-translational modification that occurs in the golgi? -
ANSWER✅ Glycosylation of outermembrane proteins to form the glycocalyx
What is indicated by a peri-nuclear clearing on cell H&E histology? - ANSWER✅ Presence
of the golgi apparatus
What is the function of ribosomes in cells? - ANSWER✅ They are responsible for protein
synthesis.
How will a high volume of ribosomes appear on histology? - ANSWER✅ Basophilic spots in
the cytoplasm
True or False: mature RBCs have ribosomes - ANSWER✅ False: only immature RBCs have
ribosomes
What is the fate of failed folded proteins? - ANSWER✅ Ubiquination and degradation by
proteosomes
