Histology Certification Cellular Structures 2

Question 1

Which organelle is responsible for post-translational modification and sorting of proteins destined for secretion?

Accepted Answer

Golgi apparatus

Answer

The Golgi apparatus processes, modifies (e.g., glycosylation), and sorts proteins received from the RER for secretion, lysosomal targeting, or membrane insertion.

Question 2

In histological sections stained with H&E, mitochondria are best described as:

Accepted Answer

Eosinophilic structures that are generally below the resolution of light microscopy as individual organelles

Answer

Mitochondria are too small (~0.5–1 µm) to be individually resolved by light microscopy; their collective contribution gives cytoplasm a diffuse eosinophilic hue.

Question 3

The inner mitochondrial membrane is characterized by extensive folding into structures called:

Accepted Answer

Cristae

Answer

Cristae are infoldings of the inner mitochondrial membrane that dramatically increase surface area for oxidative phosphorylation.

Question 4

Which cellular structure forms the primary diffusion barrier between the cytoplasm and the extracellular environment?

Accepted Answer

Plasma membrane

Answer

The plasma membrane's phospholipid bilayer is the principal selective permeability barrier regulating molecular exchange between the cell and its environment.

Question 5

Free ribosomes in the cytoplasm predominantly synthesize proteins destined for:

Accepted Answer

Cytosolic use or import into mitochondria and nucleus

Answer

Free ribosomes synthesize proteins used within the cytosol or targeted post-translationally to organelles like mitochondria, peroxisomes, and the nucleus.

Histology Certification Practice Test

Histology Certification Practice Test

Histology Certification Cellular Structures 2